Practice Parameter Contact Dermatitis: A Practice ParametereUpdate 2015
Luz Fonacier, MD, David I. Bernstein, MD, Karin Pacheco, MD, D. Linn Holness, MD, Joann Blessing-Moore, MD, David Khan, MD, David Lang, MD, Richard Nicklas, MD, John Oppenheimer, MD, Jay Portnoy, MD, Christopher Randolph, MD, Diane Schuller, MD, Sheldon Spector, MD, Stephen Tilles, MD, and Dana Wallace, MD
This parameter was developed by the Joint Task Force on Allergy & Immunology are available at http://www.JCAAI.org or Practice Parameters, which represents the American Academy of http://www.allergyparameters.org. Ó 2015 American Academy Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (J Allergy Clin Immunol of Allergy, Asthma & Immunology (ACAAI); and the Joint Pract 2015;3:S1-S39) Council of Allergy, Asthma & Immunology. The AAAAI and the Key words: Allergic contact dermatitis; patch testing; allergen; ACAAI have jointly accepted responsibility for establishing parameter; guideline; contact dermatitis; occupational; sensitizer “Contact Dermatitis: A Practice ParametereUpdate 2015.” This is a complete and comprehensive document at the current time. The medical environment is changing and not all PREFACE recommendations will be appropriate or applicable to all The Practice Parameter on Contact Dermatitis (CD) was last patients. Because this document incorporated the efforts of many updated in 2006, and focused primarily on the basics of CD and participants, no single individual, including members serving on patch testing for the allergist. In the ensuing years, there has been the Joint Task Force, are authorized to provide an official AAAAI considerable interest by the allergist in allergic skin diseases due or ACAAI interpretation of these practice parameters. Any to increasing numbers of referrals for CD. With the ease of request for information or interpretation of this practice application, the use of the preloaded commercially available parameter by the AAAAI or ACAAI should be directed to the T.R.U.E. Test patch testing method has increased among aller- Executive Offices of the AAAAI, the ACAAI, and the Joint gists, as has the use of patch testing with individually loaded Council of Allergy, Asthma & Immunology. These parameters chambers. The T.R.U.E. Test has also been expanded to include are not designed for use by the pharmaceutical industry in drug 35 antigens and a negative control, improving their sensitivity to development or promotion. Previously published practice detect inclusive allergens. There have also been advances in the parameters of the Joint Task Force on Practice Parameters for field in many areas including our basic understanding of type IV hypersensitivity reactions, emerging contact allergens, irritant contact dermatitis (ICD), systemic contact dermatitis (SCD), patch testing in children, occupational dermatitis, and reactions See Appendix A for members of the Joint Task Force Contact Dermatitis Parameter to biomedical devices. Improved diagnosis and management of Workgroup, reviewers of this Practice Parameter, and members of the Joint Task Force on Practice Parameters. CD and availability of more comprehensive databases of causa- Disclosure of potential conflict of interest: L. Fonacier has received research and tive contact allergens enable physicians to manage allergic contact educational grants (made to Winthrop University Hospital) from Genentech, dermatitis (ACD) with avoidance of allergens the patient is Merck, and Baxter; is in the Speaker’s Bureau/Honoraria of Baxter; and is on the sensitized to and availability of lists of safe products that do not Board of Directors, Joint Council of Allergy, Asthma and Immunology (JCAAI) fi 2012-2015. D. Bernstein is the consultant in Merck, Genentech, Proctor and contain these allergens. Given the many advances in the eld, the Gamble, Sanofi, and TEVA; and has received research grants from Amgen, Joint Task Force on Practice Parameters (JTF) appointed a GlaxoSmithKline, Greer, Johnson & Johnson, Merck, Teva, Pfizer, Genentech, working group to review and update the standing practice Array, Cephalon, Novartis, Boeringer Ingelheim, and Medimmune. The rest of the parameters. fl authors declare that they have no relevant con icts of interest. The Contact Dermatitis: A Practice ParametereUpdate 2015 The Joint Task Force recognizes that experts in a field are likely to have interests that could come into conflict with the development of a completely unbiased and workgroup was commissioned by the JTF to develop a practice objective practice parameter. To take advantage of that expertise, a process has parameter that addresses recent advances in the field of CD and been developed to prevent potential conflicts from influencing the final document the optimal methods of diagnosis and management based on an in a negative way. assessment of the most current literature. The Chair (Luz At the workgroup level, members who have a potential conflict of interest either do not participate in discussions concerning topics related to the potential conflict or Fonacier, MD) invited workgroup members to participate in the if they do write a section on that topic, the workgroup completely rewrites it parameter development who are considered to be experts in the without their involvement to remove potential bias. In addition, the entire docu- field of CD. Workgroup members have been vetted for conflict ment is then reviewed by the Joint Task Force and any apparent bias is removed at of interest (COI) by the JTF and their COIs have been listed in that level. Finally, the practice parameter is sent for review both by invited re- this document and are posted on the JTF web site at http://www. viewers and by anyone with an interest in the topic by posting the document on the web sites of the ACAAI and the AAAAI. allergyparameters.org. Corresponding author: Joint Task Force on Practice Parameters, 59 N Brockway St, The charge of the workgroup was to develop current practice #304, Palatine, IL 60067. E-mail: [email protected]. guidelines based on an up-to-date systematic literature review. Received for publication February 25, 2015; accepted for publication February 26, Consensus expert opinion and workgroup-identified supplementary 2015. 2213-2198 documents were utilized when published evidence was lacking. Ó 2015 American Academy of Allergy, Asthma & Immunology A search of the medical literature on PubMed was performed http://dx.doi.org/10.1016/j.jaip.2015.02.009 for a variety of terms that were considered to be relevant to this
S1 S2 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015
practice parameter. All reference types were included in the re- Abbreviations used sults. References identified as being relevant were searched for AA- Amidoamine other relevant references. Published clinical studies were rated by AAAAI- American Academy of Allergy, Asthma and Immunology category of evidence and utilized to establish the strength of the ACAAI- American College of Allergy, Asthma and Immunology recommendations (see Appendix B). The parameter was subse- ACC- Allergic contact cheilitis ACD- Allergic contact dermatitis quently appraised by reviewers designated by the AAAAI and ACDS- American Contact Dermatitis Society ACAAI. Based on this process, this parameter represents an ev- AD- Atopic dermatitis idence-based, broadly accepted consensus document. AGEP- Acute generalized exanthematous pustulosis Search terms include contact dermatitis, eczema, cosmetic APT- Atopy patch test allergy, contact allergen, patch testing, and each of the specific BOP- Balsam of Peru conditions reviewed in this parameter. BTM- Betamethasone CAMP- Contact Allergen Management Program CAPB- Cocoamidopropyl betaine GLOSSARY CARD- Contact Allergen Replacement Database “Angry back” syndrome or “excited skin” syndrome:defined CD- Contact dermatitis as false-positive patch test (PT) reactions usually adjacent to large CLO- Clobetasol true-positive reactions that induce contiguous skin inflammation fl COI- Con ict of interest and irritability. CS- Corticosteroid Ectopic allergic contact dermatitis: contact allergy lesions CU- Contact urticaria DMAPA- Dimethylaminopropylamine manifested in locations distant from or indirectly in contact with DRESS- Drug rash with eosinophilia and systemic symptoms the original skin sites directly exposed to allergens due to inad- ELISA- Enzyme-linked immunosorbent assay vertent transfer by the patient (eg, transfer of sensitizers in nail EliSPOT- Enzyme-linked immunospot polish to the eyelids) or others (eg, mother transferring allergen ENDA- European Network on Drug Allergy to the child or a partner transferring the allergen by contact). ESCD- European Society of Contact Dermatitis Contact sensitization: evidence of sensitization such as pos- FDA- Food and Drug Administration itive PT reaction is not definitive of an “allergy” but simply a FM- Fragrance mix confirmation of immunologic sensitization that must then be FM I- Fragrance mix I confirmed as clinically relevant by history and clinical findings FM II- Fragrance mix II analysis. GCDG- German Contact Dermatitis Group Contact urticaria: defined as the development of a wheal- HC- Hydrocortisone fl ICD- Irritant contact dermatitis and- are reaction at a site where an external agent contacts the IM- Intramuscular skin or mucosa. IPPD- Isopropyl-para-phenylenediamine Late patch test reading: late PT reading is performed at or IUDs- Intrauterine devices after 7 days after application of a PT as opposed to the standard IV- Intravenous of care reading that is performed between day 3 and 7. LPTs- Lymphocyte proliferation tests Photo-allergic contact dermatitis: it is a delayed contact MCI- Methychloroisothiazolinone hypersensitivity reaction to an allergen activated by exposure to MELISA- Memory Lymphocyte Immuno Stimulation Assay UV radiation. MI- Methylisothiazolinone Repeated open application test (ROAT): several open PT MPL- Methylprednisolone MSDS- Material safety data sheets techniques have been used to test substances with the potential for NACDG- North American Contact Dermatitis Group irritation, and are especially suitable for cosmetics and other per- NHIS- National Health Interview Survey sonal care products such as makeup foundation and skin lotions. NS- Nasal spray The more commonly used provocative open use test involves the NSAIDs- Nonsteroidal anti-inflammatory drugs repeated application of a suspected allergen to the antecubital fossa OCD- Occupational contact dermatitis twice daily for up to 1 to 2 weeks, and observation for the local OHS- Occupational health supplement development of dermatitis at the application site. PABA- Para-aminobenzoic acid Usage test: use of a product highly suspected of containing a PPD- Para-phenylenediamine sensitizer under real world conditions to prove causation. An PT- Patch test example is for a patient to use eye mascara daily on 1 eye and not PTDS- Para-toluenediamine sulfate ROAT- Repeated open application test the other to observe for the development of local dermatitis at the SCD- Systemic contact dermatitis exposed site. This is often used when PT with suspected com- SJS- Stevens Johnson syndrome mercial allergens is negative but the suspicion of ACD is high. TCI- Topical calcineurin inhibitors Systemic allergic contact dermatitis: a generalized ACD rash TCL- Triamcinolone from systemic administration of a drug, chemical, or food to TCS- Topical corticosteroids which the patient previously experienced ACD. TEN- Toxic epidermal necrolysis UK- United Kingdom UVA- Ultraviolet A INTRODUCTION UVB- Ultraviolet B Contact dermatitis (CD) is defined as any skin disorder caused by contact with an exogenous substance that elicits an allergic J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S3 VOLUME 3, NUMBER 3S and/or irritant response. The vast majority of cases are attribut- evidence is impossible to obtain, and the anticipated benefits able to irritant ICD. CD is also a significant cause of workplace strongly outweigh the harms. disability. Overall, this is a practical, clinically pertinent, and user- Contact urticaria (CU) is defined as the development of a wheal- friendly parameter that has attempted to address important and-flare reaction, or hives, at a site where an external agent contacts clinical questions pertaining to the evaluation and management the skin or mucosa. CU can be divided in 2 broad categories: of ACD. This document, although not intended to replace an nonimmunologic CU and immunologic CU (caused by an IgE- authoritative textbook, is a valuable updated evidence-based mediated hypersensitivity reaction). Symptoms of CU range from resource for the practicing allergist. pruritic, localized wheal-and-flare reactions to generalized urticaria and anaphylaxis. Aside from the need to differentiate between ACD and CU, this parameter will not discuss CU in detail. COMPILATION OF SUMMARY STATEMENTS This CD practice parameter, updated from the original docu- Summary Statement 1: Consider ACD in the differential ment published in 2006, is intended as a useful guide for the diagnosis of patients with chronic eczematous or noneczematous practicing allergist in the evaluation and management of ACD in dermatitis. [Strength of Recommendation: Strong; C Evidence] adults and children. This updated parameter has been restructured Summary Statement 2: In patients suspected of ACD, patch around action-based and patient-centered summary statements that testing is the gold standard to confirm the diagnosis. [Strength of provide specific evidence-based recommendations for assessing and Recommendation: Strong; C Evidence] treating ACD. In contrast to the original 2006 parameter, the Summary Statement 3: In addition to personal products used pathophysiology, susceptibility, and clinical background are not by a patient suspected of ACD, review the home and workplace reviewed here. The evidence-based summary statements in this for other sources of contact allergens. [Strength of Recommen- document provide specific recommendations pertaining to the dation: Moderate; D Evidence] approach to medical history, physical examination, patch testing, Summary Statement 4: Evaluate patients for both irritant and and management of patients suspected of ACD. allergic causes, especially in those presenting with hand derma- As in the 2006 parameter, action-based summary statements titis. [Strength of Recommendation: Strong; C Evidence] provide guidance for identification of potential causative sensi- Summary Statement 5: Allergic CD should be suspected and tizers based on clinical presentation in specific geographical skin evaluated in the patient with both generalized and anatomically locations. Patch testing is emphasized in this updated parameter, localized skin eruptions (such as the hands, face, eyelids) that with action-based statements that address selection of PT anti- come in contact with the substances in the environment. gens; testing to personal products when necessary; different patch [Strength of Recommendation: Moderate; C Evidence] testing devices; timing of readings; late PT reactions; false-posi- Summary Statement 6: In a patient with a facial rash involving tive, false-negative, and true-negative responses; and photo-patch the periorbital areas (eg, eyelids), evaluate for ACD caused by testing. Lists of sensitizers encountered in different settings or in components of cosmetics, such as fragrances, preservatives, and specific types of products (eg, cosmetics, sunscreens, joint pros- excipients, because these are common sensitizers of the facial theses) are presented as tables in the appendices. skin. [Strength of Recommendation: Moderate; C Evidence] Since the publication of the original parameter, new questions Summary Statement 7: Evaluate patients presenting with lip have been addressed in summary statements related to emerging dermatitis (cheilitis) and perioral dermatitis for both irritant and clinical problems including preoperative screening for and post- allergic causes of contact dermatitis. [Strength of Recommen- implantation patch testing for metal allergy in patients who have dation: Moderate; C Evidence] undergone joint replacement surgery. In this updated practice Summary Statement 8: Evaluate patients with chronic oral parameter, summary statements have been added that more mucosal inflammatory conditions for disorders other than ACD. comprehensively address evaluation and management of occupa- [Strength of Recommendation: Moderate; C Evidence] tional contact dermatitis (OCD). The potential benefits and limi- Summary Statement 9: In patients presenting with dermatitis tations of drug patch testing in patients with maculopapular rashes, that involves the scalp and neck, consider patch testing for erythroderma, and nonimmediate cutaneous reactions are addressed common causative sensitizers in cosmetics, hair products, and in a summary statement. New summary statements have been jewelry. [Strength of Recommendation: Moderate; C Evidence] included that make recommendations pertaining to the overall Summary Statement 10: Consider irritant and ACD in all management of CD, focusing on avoidance and prevention. patients presenting with acute or chronic hand eczema. All such The majority of summary statements in this document are patients suspected of CD should undergo patch testing. based on descriptive and retrospective studies, representative [Strength of Recommendation: Moderate; C Evidence] of the current published CD literature. Because the treat- Summary Statement 11: Evaluate patients with axillary ment of choice for CD is avoidance, there are limited dermatitis for ACD caused by local contact sensitivity to allergens numbers of published placebo-controlled studies of other in topically applied products found in deodorants and textiles. In therapeutic interventions (eg, drugs). The absence of a vali- some cases, axillary dermatitis could be a manifestation of systemic dated positive control to confirm a diagnosis of ACD is a contact dermatitis (SCD) (ie, “the baboon syndrome”). [Strength major limitation of studies reporting patch testing data. For of Recommendation: Moderate; C Evidence] these reasons, the categories of evidence supporting the Summary Statement 12: Evaluate patients presenting with summary statements in this document are relatively low. anogenital dermatitis for possible ACD to antigens contained in Therefore, the strength of recommendation for most of the topically applied products. [Strength of Recommendation: statements in this parameter is “Moderate” even if in some Moderate; C Evidence] clearly identified circumstances, “Strong” recommendations Summary Statement 13: Consider a diagnosis of SCD may be made based on lesser evidence because high-quality following systemic exposure (eg, ingestion, infusion, or S4 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015 transcutaneous exposure) to a known contact sensitizer in a pa- Summary Statement 23: Determine the relevance of a PT result tient who presents with generalized dermatitis, intertriginous and based on the clinical and exposure history when interpreting the flexural exanthema (Baboon syndrome), and/or a flare at previ- PT. [Strength of Recommendation: Moderate; D Evidence] ous cutaneous sites of exposure [Strength of Recommendation: Summary Statement 24: Consult physicians with expertise in Moderate; C Evidence]. patch testing to household cleaning or industrial products if Summary Statement 14: Consider PT to rubber chemicals, testing to the actual product suspected of containing the relevant adhesives, and leather components of footwear in patients pre- allergen(s) is necessary, because false-positive and severe irritant senting with unexplained chronic dermatitis involving the lower reactions can occur. [Strength of Recommendation: Moderate; C extremities, feet and/or soles. [Strength of Recommendation: Evidence] Moderate; C Evidence] Summary Statement 25: Consult physicians with expertise in Summary Statement 15: In addition to avoiding irritants in UV radiation and photo-patch testing to confirm a suspected patients with atopic dermatitis (AD), evaluate for ACD, if sus- diagnosis of photo-allergic CD. [Strength of Recommendation: pected, as the 2 dermatologic conditions often coexist in the Strong; C Evidence] same patient. [Strength of Recommendation: Moderate; C Summary Statement 26: Although in vitro tests for delayed Evidence] hypersensitivity to contact allergens (ie, metals and bone cement) are available, routine use of such assays is not currently recom- Patch testing recommendations mended as their sensitivity and specificity for diagnosing ACD Summary Statement 16: Avoid or reduce doses of immuno- has not been determined and should be considered investiga- suppressant medications such as systemic corticosteroids (CS) tional. [Strength of Recommendation: Moderate; C Evidence] and systemic immunosuppressants before patch testing. Avoid Summary Statement 27: Use the repeated open application application of topical corticosteroids (TCS), topical calcineurin test (ROAT) to further evaluate a patient suspected of ACD who inhibitors (TCI), or ultraviolet radiation to the PT site, because exhibits doubtful or negative PT responses, to confirm that the these may reduce allergic PT responses. [Strength of Recom- patient is reacting to that particular product or to determine mendation: Moderate; C Evidence] clinical tolerability to new cosmetic products. [Strength of Summary Statement 17: In addition to using a core or base- Recommendation: Moderate; C Evidence] line series of PT allergens in evaluating ACD, consider using supplemental series of PT allergens based on specific patient Sources of exposure to clinically relevant allergens exposures, and the patient’s personal products to increase the Summary Statement 28: Evaluate patients who present with probability of identifying relevant sensitizers. [Strength of recurrent dermatitis on exposed skin surfaces during airborne Recommendation: Moderate; C Evidence] pollen seasons for contact sensitization to seasonal pollen aller- Summary Statement 18: Patch testing can be performed either gens. [Strength of Recommendation: Moderate; C Evidence] using a preloaded thin-layer rapid use epicutaneous testing kit of Summary Statement 29: The clinician should consider cos- 36 chambers or with a panel of antigens loaded individually in a metics and personal hygiene products that are directly applied to chamber system recommended by the North American Contact involved skin or ectopically transferred from uninvolved skin as Dermatitis Group (NACDG) Research Group or the American potential sources of allergens in patients with ACD. [Strength of Contact Dermatitis Society (ACDS). [Strength of Recommen- Recommendation: Strong; C Evidence] dation: Moderate; C Evidence] Summary Statement 30: When evaluating ACD from cos- Summary Statement 19: Read and interpret PT conforming to metics and personal care products that contain many different the scoring system developed by the International Contact chemical ingredients, consider that the most common causes are Dermatitis Research Group. [Strength of Recommendation: due to a few important chemical classes, including fragrances, Moderate; D Evidence] preservatives, excipients, nickel, and sun screening agents. Summary Statement 20: Remove and read PT at approxi- [Strength of Recommendation: Moderate; C Evidence] mately 48 hours after application. A second reading should be Summary Statement 31: Patients suspected to have allergy to done between 3 and 7 days after application. [Strength of hair products should be evaluated for PT reactions to cocoami- Recommendation: Moderate; C Evidence] dopropyl betaine (CAPB), para-phenylenediamine (PPD), fra- Summary Statement 21: Consider that a possible false-positive grances, preservatives, and glycerol thioglycolate. [Strength of reaction can result with the use of irritants or allergic substances Recommendation: Moderate; C Evidence] at potentially irritating higher concentrations, pressure reaction Summary Statement 32: Suspect allergy to nail products when from the filling chamber, an “angry back syndrome,” or patch the dermatitis presents locally at the distal digit or ectopically on testing on skin with active dermatitis. [Strength of Recommen- the eyelids and face. [Strength of Recommendation: Moderate; C dation: Moderate; D Evidence] Evidence] Summary statement 22: Recognize the possibility that Summary Statement 33: Suspect the diagnosis of photo- false-negative reactions could be due to inadequate allergen allergic CD to cosmetics when eczema occurs in a light-exposed concentration needed to elicit a response; inability of the distribution following the use of a skin care product or cosmetic, vehicle to release sufficient allergen; reduced skin respon- including sunscreens. [Strength of Recommendation: Strong; C siveness because of prior ultraviolet light exposure (ie, sun, Evidence] tanning bed); concomitant immunosuppressive therapies; or methodological testing errors such as insufficient occlusion, Topical medicinal CD failure to perform delayed readings, and failure to perform a Summary Statement 34: If an eruption worsens, rather than photo PT. [Strength of Recommendation: Moderate; C improves, after the topical application of certain medications, or Evidence] fails to respond to TCS, PT should be performed to the J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S5 VOLUME 3, NUMBER 3S suspected product and/or ingredients known to be contact sen- these should be considered in the differential diagnosis. The sitizers. [Strength of Recommendation: Moderate; C Evidence] suspicion of ACD is the first step in making the diagnosis. Patch Summary Statement 35: The clinician may use the drug PT testing is indicated in any patient with acute or chronic, often for the diagnosis of some drug hypersensitivity reactions, recog- pruritic, dermatitis if underlying or secondary ACD is suspected. nizing that there is no standardized approach to define the The history is important for the diagnosis and subsequent population, clinical manifestation, drug to PT, and PT materials management of this disease. Although medical history can to make patch testing to drugs a standard of care. [Strength of strongly suggest the cause of ACD, it has moderate sensitivity Recommendation: Weak; D Evidence] (76%) and specificity (76%) in establishing the diagnosis. In Summary statement 36: Consider preoperative patch testing for addition, the occupational, avocational, and environmental his- metal sensitization in patients with a significant history of metal tory must all be carefully reviewed. Chronologic exposure his- allergy. [Strength of Recommendation: Moderate; C Evidence] tories that include hobbies and specific activities relative to onset Summary Statement 37: In patients with joint replacement of the dermatitis should be obtained. Because the worker may be failure, patch testing to components of the implant may be unaware of specific chemicals to which he or she is exposed, helpful after infection and biomechanical causes have been material safety data sheets (MSDS) obtained from the manu- excluded. [Strength of Recommendation: Moderate; C Evidence] facturer may be helpful. Hobbies and nonwork activity such as gardening, macramé, painting, ceramic work, carpentry, and Special populations photography may be sources of exposure to culprit contactants. Contact dermatitis in children. Summary Statement 38: In addition to exposure to a single agent, simultaneous exposure ACD and ICD are significant clinical problems in children. to multiple irritants and contact allergens may produce additive, Patch testing should be performed and remains the gold standard synergistic, or antagonistic responses. Simultaneous exposure to for the diagnosis of ACD in children. [Strength of Recommen- both an irritant and a contact allergen or 2 contact allergens can dation: Strong; C Evidence] reduce the clinical threshold concentration for elicitation of response to a given allergen due to irritant disruption of the skin Occupational contact dermatitis. Summary Statement barrier and immunologic activation of the skin. 39: In a patient who presents with dermatitis associated with There is conflicting evidence as to whether patients with AD workplace exposures (ie, OCD), consider ICD as well as ACD. are at heightened overall risk of contact sensitization compared [Strength of Recommendation: Strong; C Evidence] with nonatopic individuals. Because AD is associated with an Summary Statement 40: In patients with suspected occupa- impaired skin barrier, it is plausible that this impairment is likely tion-related CD, the examining physician should verify the to increase absorption of topically applied chemicals and enhance diagnosis by confirming that the dermatitis was caused or the risk of subsequent sensitization, resulting in ACD and aggravated by workplace exposures. [Strength of Recommenda- worsening of the underlying dermatitis. In children with severe tion: Moderate; C Evidence] recalcitrant AD and concomitant ACD, avoidance of offending Summary Statement 41: Consider botanical-related ACD in allergens in topically applied products can result in marked outdoor workers, or others exposed to plants, including florists, improvement of eczema. gardeners, landscapers, maintenance workers, park, and wildlife The latest NACDG lists the top 3 most common body lo- officials. [Strength of Recommendation: Moderate; C Evidence] cations of contact dermatitis as scattered and/or generalized distribution, the hands, and the face. In addition, attention Treatment of contact dermatitis. Summary Statement fi fi should be given to speci c anatomical sites, particularly the 42: Once the allergen or irritant has been identi ed, the patient eyelids, neck, scalp, axillae, lower extremities, and anogenital should be counseled on avoidance of contact with the offending area. Facial ACD may present as a generalized facial eruption or agent and informed of any cross-reactivity concerns. [Strength of in specific regions such as the forehead, periorbital, or perioral Recommendation: Strong; B Evidence] areas. Sensitizers in commercial facial products that are in direct Summary Statement 43: In addition to avoidance of exposure, skin contact are the most common causes of facial ACD. the physician should prescribe appropriate adjunct medical Patients presenting with acute or chronic hand eczema should treatment. [Strength of recommendation: Strong; B Evidence] undergo patch testing. Although most cases of CD involving the Summary Statement 44: To prevent CD, avoid exposure to hands are caused by irritants, allergic contact sensitization is a irritants and allergens and use appropriate skin protection. common cause of chronic hand dermatitis. The prevalence of [Strength of Recommendation: Strong; B Evidence] ACD in patients presenting with hand dermatitis or hand eczema Summary Statement 45: Education of the workers with ACD varies according to exposure history and occupation. Thus, it is or ICD should include prognosis, and information that their strongly recommended to evaluate all patients with chronic hand disease may persist and need long-term management even after fi eczema for ACD by obtaining a medical history of contact allergy treatment and workplace modi cations. [Strength of Recom- and performing patch testing. mendation: Moderate; C Evidence] Acute or chronic inflammation of the lips manifested as eczematous cheilitis can be characterized by itching, burning, EXECUTIVE SUMMARY redness, edema, and fissuring. This is most commonly caused by Contact dermatitis may be suspected on the basis of the physical (eg, cold, dryness, wind) or chemical irritants (eg, saliva, clinical appearance of the cutaneous lesions, the distribution of lip cosmetics, or other oral products). Fragrance mix (FM), the dermatitis, and the absence of other etiologies. Acute CD is balsam of Peru (BOP, Myroxylon pereirae), and nickel are the characterized by erythematous papules, vesicles, and crusted le- most common positive allergens on PT. Sources of fragrances sions. There are other dermatological conditions that may include oral hygiene products (eg, toothpastes, mouthwashes, resemble the clinical and/or histological appearance of CD, and flavorings, compounds used for dental impressions), cosmetics, S6 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015 and lip products (including lipsticks, glosses, and lip balms). Oral Patch testing is indicated in any patient suspected of ACD. contact sensitization is considered to be uncommon. Persistent Patch testing can be performed using either a preloaded thin- oral complaints or gingivitis has been associated with positive PT layer rapid use epicutaneous testing kit of 36 chambers or with a reactions to allergens in dental components, including mercury, panel of antigens individually loaded in a chamber system rec- methacrylate, and beryllium. Chemical and traumatic injury may ommended by the NACDG Research Group or the ACDS. The be the most common causes of contact reactions involving mu- T.R.U.E. Test (panel of 35 antigens and a negative control) (see cous membranes. Other conditions that should be considered in Appendix H) is standardized across lot numbers and is highly patients with oral mucosal inflammation include burning mouth reproducible. Depending on the test antigen, the T.R.U.E. Test syndrome, lichenoid tissue reactions, stomatitis, gingivitis, oro- method has moderate concordance (62% to 63%) with indi- facial granulomatosis, recurrent aphthous stomatitis, precancer- vidually loaded chamber systems (eg, Finn chamber system). ous and cancerous lesions, viral and fungal infections and lichen Reliance on a core or baseline series of PT antigens such as those planus. used by the NACDG Research Group or in the T.R.U.E. Test In patients presenting for patch testing for evaluation of CD, panel for assessing all patients is likely to lead to underdiagnoses nickel remains the most common contact sensitizer and is found of ACD. Selection of allergens to be patch tested will be more more frequently in women than it is in men. The gender dif- accurate when selection is based on the clinical history. One can ference is likely due to greater exposure of the neck, hands, and use PT panels based on the specific industry or exposure group. ears to nickel in jewelry and body piercing practices. Females are Frequently, especially in the eyelid, lip, and facial dermatitis, it twice as likely as males to have ACD involving the head and neck may be necessary to include personal products and substances due to cosmetics. Among patients with cosmetic allergies, fra- specific to the patient’s exposure history. grances, preservatives, and emulsifiers are the most common Commercially available panels of supplemental allergens that causative allergens. In addition to the most common hair dye are constituents of personal care products or encountered in sensitizer, PPD, there are sensitizers in shampoos, including specific occupational environments are listed in the Appendices fragrances, CAPB, and preservatives. ACD involving the scalp is B, C, and D. frequently caused by allergens in personal hygiene and medical The International Contact Dermatitis Research Group’s products (eg, neomycin, benzocaine), hair tint and/or dyes, hair scoring system listed below is widely used: cleansing products, and bleaches. (-) Negative reaction ACD involving the axillary region is often due to contact (?þ) Doubtful reaction with faint erythema only sensitivity to fragrance chemicals in deodorants; antiperspirant (1þ) Weak positive reaction with nonvesicular erythema, chemicals are uncommon causes of ACD. Allergic CD due to infiltration, possibly papules disperse dyes in clothing can elicit eczematous eruptions in the (2þ) Strong positive reaction with vesicular erythema, infil- axillae, feet, and groin. Axillary dermatitis may be a manifestation tration, and papules of SCD, specifically the “baboon syndrome,” a diffuse eruption (3þ) Extreme positive reaction with intense erythema and involving flexural and intertriginous areas following oral, infiltration, coalescing vesicles, bullous reaction intravenous, or transcutaneous exposure to the allergen in a (IR) Irritant reaction contact-sensitized individual. Three groups of allergens are most (NT) Not tested common causes of SCD: (i) metals such as mercury, nickel, and In the evaluation of delayed hypersensitivity reactions, the gold; (ii) medications including aminoglycoside antibacterials, initial reading of PT should be done approximately 48 hours CS, and aminophylline; and (iii) plants and herbal products after their application following patch removal. Tests may need including Compositae and Anacardiaceae families and BOP (also to be read 30 minutes after removal of the patches to allow er- known as Myroxylon pereirae). ythema from the occluding pressure of the tape and/or chamber Patients presenting with anogenital dermatoses have been to resolve. A second reading must be done; this is often done at diagnosed with confirmed ACD to allergens contained in topi- day 3 to 7 after the initial application. A collaborative study cally applied products such as cosmetics, medications, feminine demonstrated that 30% of relevant allergens were positive at 96 hygiene and contraceptive products. The most common sources hours and were negative at the 48-hour reading, which suggests of antigens were topical medications, including TCS, fragrances, that 96 hours may be optimal for a second reading. Occasionally, BOP, nickel sulfate, cinnamic aldehyde, and neomycin sulfate. an additional late reading after 7 days may be needed for certain The preservative methylisothiazolinone (MI) and benzocaine contactants such as metals, some antibiotics, and TCS that may were frequently identified as contact allergens in patients with yield late reactions. Oral CS exceeding 20 mg/day of prednisone anogenital complaints. or its equivalent have been shown to diminish skin test reactivity The pattern of foot dermatitis due to ACD varies according to to 5% nickel sulfate at 48 hours. There is minimal evidence to the type of footwear used. Para-tertiary butylphenol formaldehyde guide the duration of steroid reduction or withdrawal before resin (in adhesives), potassium dichromate, cobalt chloride, and performing patch testing. If the clinical suspicion is high despite carbamates are among the most common allergens. Allergic CD a negative PT in a patient receiving immunosuppressive medi- involving the feet is commonly caused by sensitization to common cations, consider repeat testing when the immunosuppressant rubber allergens (carbamates, thiurams, and mercaptobenzothia- doses are lowered or discontinued. The test site where the PT are zole). Children presenting with sole dermatitis should be evaluated applied should have no topical potent CS or TCI applied for 5 to by patch testing to rule out ACD caused by rubber additives, ad- 7 days before testing. UV irradiation of PT sites before testing hesives, and/or chromates. The majority of patients with chronic can suppress PT responses. leg ulcers and leg dermatitis have contact sensitization to chemical Doubtful (?þ) or weakly positive (1þ) questionable or irre- sensitizers found in topically applied preparations including BOP, producible reactions on PT can be easily misinterpreted. The FMs, antibacterial agents, CS, and lanolin. timing of the response may also affect its clinical significance, J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S7 VOLUME 3, NUMBER 3S with a weak reaction at day 7 more likely to be clinically relevant When evaluating ACD from cosmetics and personal care than one at day 3. The inability to separate nonspecific from true products that contain many different chemical ingredients, allergic responses may be due to the “angry back” or “excited consider that the most common causes are due to a few skin” syndrome, which is defined as false-positive reactions important chemical classes, including fragrances, preservatives, adjacent to large true-positive reactions that induce contiguous excipients, nickel, and sun blocks. Fragrances are complex sub- skin inflammation and irritability. The frequency of false-nega- stances and are the most common cause of ACD from cosmetic tive results is not known, but has been estimated to occur in up in the United States. Previous studies suggest that the standard to 30% of patch-tested patients. The ROAT is used to further FM and BOP will detect approximately 60% to 70% of evaluate a patient suspected of ACD who exhibits doubtful or fragrance-allergic individuals. The addition of other commonly suspected false-negative PT responses, to confirm that the patient used fragrance ingredients (FM II, lyral, ylang ylang oil, narcissus is reacting to that particular product or to determine clinical oil, and sandalwood oil) may increase the yield up to 96%. tolerability to new cosmetic products. The threshold concen- However, it should be noted that fragrances in PT have marginal tration for a positive reaction for the ROAT is lower than the irritant potential and weak positive reactions may not be regar- threshold concentration for a positive PT, although the accu- ded as proof of contact sensitization (low specificity of the test). mulated ROAT dose was very similar to the PT. Preservatives and antibacterials are used to prevent rancidity The clinical relevance of positive PT reactions to ACD can and microbial contamination. Preservatives tend to be grouped only be established by carefully correlating the history, which into 2 broad categories: formaldehyde releasers (products that includes exposure to the allergen, with the PT results. A positive emit formaldehyde) and nonformaldehyde releasers. It is rec- PT may be clinically relevant depending on current or past ex- ommended that patients allergic to formaldehyde be advised to posures. Current relevance is defined as definite if the PT or use avoid stay-on cosmetics preserved with formaldehyde releasers. test with the suspected material is positive; probable if the PT is Among nonformaldehyde releaser preservatives, methlydibromo positive and the antigen is present in known skin contactants and gluteronitrile and methychloroisothiazolinone/methyl- the clinical presentation is consistent with that exposure; or isothiazolinone (MCI/MI) (trade name: Kathon CG) have possible if the PT is positive, and skin contact with materials emerged as an important cosmetic and toiletry allergen with known to contain the allergen was likely. increasing prevalence. The use of MI alone as a preservative in If photo-allergic CD is suspected, physicians should be con- personal care and cosmetic products has increased in the past few sulted with expertise in UV radiation and photo-patch testing to years especially in rinse-off products such as shampoos, condi- confirm a suspected diagnosis. Photo-allergic CD typically affects tioners, baby soaps and detergents, and wet wipes. Although sun-exposed areas such as the face, the ‘‘V’’ of the anterior neck, parabens formulated in cosmetics are infrequent causes of ACD, the dorsal hands, and forearms. It typically spares the upper they can induce ACD when used as antibacterial in topical eyelids, upper lip, and submental and postauricular areas. The medications especially those used on damaged skin, such as in more common cause of sunscreen sensitization is the chemical long-standing dermatitis and stasis ulcers. The rate of sensitiza- sunscreens. Titanium dioxide and zinc oxide (physical UV tion to parabens in patients with chronic leg ulcers is higher than blockers) have not been reported to cause ACD or photo-allergy, that of the general population. although there are a few reports of titanium in implants causing “Botanicals” (such as tea tree oil, propolis, and other essential ACD. Testing requires duplicate application of allergen with oils) are plant extracts that are increasingly used as additives to subsequent occlusion, and irradiation of one side to compare to skin care products and are potential causes of CD. It is important the other, nonirradiated application. that patients who are allergic to fragrance also be made aware of Although in vitro tests for delayed hypersensitivity to contact the potential dangers of cosmetic products that may contain allergens (ie, metals and bone cement) are available, routine use of plant extracts and patients should also be counseled that “natural such assays is not currently recommended as their sensitivity and products” does not equate with safety. specificity for diagnosing ACD has not been determined and should In patients suspected to have allergy to hair products, CAPB, be considered investigational. In vitro tests for assessing antigen PPD, fragrances, preservatives and glycerol thioglycolate should specific sensitization are based on measuring lymphocyte prolifera- be considered. CAPB is an amphoteric surfactant that is often tion (lymphocyte proliferation tests—LPTs) or cytokine production found in shampoos, bath products, and cleaners. Allergy to (ELISA or EliSPOT) after incubation with antigens. Some in vitro CAPB typically presents as eyelid, facial, scalp, and/or neck tests have been validated against patch testing, whereas others have dermatitis. Paraphenylenediamine is the active ingredient in not. The clinical relevance of in vitro testing to the diagnosis of CD many hair dyes, and is a very common cause of CD in hair- has not been established and is still investigational. dressers. Other routes of exposure include body painting and Identifying sources of exposure to clinically relevant allergens temporary tattooing. ACD from PPD can be severe, sometimes is challenging. Dermatitis present on the face, hands, and mimicking angioedema. Cross-reactivity of PPD with other exposed chest may be triggered by airborne protein allergens such para-amino compounds, such as benzocaine, para-amino- as grass pollen, house dust mite, and cat dander; and diagnosed benzoic acid (PABA), sulfa drugs, aminoazobenzene, isopropyl- by the application of the allergen by patch testing. CD caused by para-phenylenediamine (IPPD), and azo dyes has been reported cosmetics is noted predominantly at the site of application; and may require avoidance. Glycerol thioglycolate is the active however, occasionally personal care products and cosmetics ingredient in permanent wave solution and tends to cause more manifest the contact allergy lesions in locations distant from the occupational dermatitis in hair dressers than consumers. Thi- original skin sites. This phenomenon termed ectopic CD can be oglycolates may remain allergenic in the hair long after it has caused by nickel transferred to the eyelid by fingers that have been rinsed out. been exposed to a nickel source or toluene sulfonamide formal- Allergy to nail products is suspected when dermatitis presents dehyde resin in nail polish. locally at the distal digit or ectopically on the eyelids and face. S8 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015
Most allergic reactions to nail polish and artificial nail products to experience the same symptoms. Similarly, a group of patients are to tosylamide and/or formaldehyde resin found in nail polish with implant-related eczema who were metal sensitized, and then enamel, in addition to nail hardeners and setting lacquers. Up to underwent revision with a different metal alloy implant, had a 80% of the reactions appear on the neck, face, lips, and eyelids. higher incidence of eczema resolution. Anecdotal case reports Alkyl polyester resin may be a suitable alternative for sensitive suggest that patients with skin or systemic manifestations of patients. sensitization to components of implantable defibrillators, pace- Topical medicinal CD commonly develops after exposure to makers, arterial stents, dentures, and intrauterine devices (IUDs) topical medications, including lanolin, para-aminobenzoic acid appeared to improve once the sensitizing agent was replaced. (in sunscreens), “caines” (anti-itch preparations), topical antibi- There are no current guidelines or recommendations for otics (neomycin, bacitracin), topical antihistamines, nonsteroidal symptomatic patients with positive PT to metals or bone cement anti-inflammatory drugs (NSAIDs), and/or TCS. Lanolin is used components. The decision regarding implant revision following as the base of many topical medications, including TCS and positive PT results can only be made after a thorough discussion moisturizers. Allergy to TCS affects 0.5% to 5.8% of patients between the patient, the allergist or dermatologist, and the or- suspected of ACD. PT to CS is complicated by the inherent, thopedic surgeon. In addition to the possibility of metal sensi- anti-inflammatory nature of the drug itself, which results in tization as a potential cause of joint replacement failure, there are frequent false-negative results if tested at too high concentration also reports of implant failure related to bone cement or its or late PT readings (7-10 days following application) are not components including benzoyl peroxide, hydroquinone, methyl done. Coopman et al classified 4 major groups of CS prepara- methacrylate, and n,n-dimethyl para-toluidine. tions based on 2 immune recognition sites with considerable In considering special populations, both ACD and ICD are cross-reactivity within the groups. Testing should include tix- significant clinical problems in children. Patch testing should be ocortol pivalate, budesonide, triamcinolone, the patient’s com- performed and remains the gold standard for the diagnosis of mercial steroid, the vehicle, and the preservatives in the ACD in children. In children, a careful, age-appropriate history preparations. Although rare, patients sensitized to TCS can should include exposure to diapers, hygiene products, personal develop SCD with administration of the CS by an oral, IV, IM, care products, cosmetics, sunscreens, textiles with dyes and fire or inhalation route. retardant materials, medications, pets and pet products, school PT to drugs may have a role in delayed hypersensitivity drug projects, sports, and so on. A US-based study showed nickel, reactions and have a higher positivity in patients presenting with fragrance, cobalt, thimerosal, BOP, potassium dichromate, maculopapular rashes, erythroderma, and nonimmediate cuta- neomycin, lanolin, thiuram mix, and PPD to be common al- neous reactions including drug rash with eosinophilia and sys- lergens in children. In addition, there are highly relevant aller- temic symptoms (DRESS), acute generalized exanthematous gens that have significant frequency in children because of their pustulosis (AGEP), Stevens Johnson syndrome/toxic epidermal unique exposure such as MCI/MI, dialkyl thiourea, p-tert-butyl necrolysis (SJS/TEN), and fixed drug eruptions. The utility of formaldehyde resin, CAPB, and disperse dyes. the PT depends on various factors including the type and Contact dermatitis is one of the most common types of formulation of the drug being tested, the vehicle used, as well as occupational illness, with estimated annual costs exceeding $1 the immunopathogenesis eliciting the eruption. Currently, there billion. OCD is classically divided into ICD and ACD. ICD is no standardized approach to define the population likely to represents approximately 80% of all cases of OCD and most benefit and validated PT materials to make PT to drugs a stan- commonly involves the hands. Common irritant exposures dard of care. include wet work, solvents and alcohols, cutting oils, coolants, Indications for pre-operative patch testing in patients with a degreasers, soaps, detergents, and other cleaning agents and history of metal allergy are still being studied. However, pre- disinfectants. The major chemical groups associated with ACD operative PT may help guide the selection of implant alloys in include metals, rubber-related materials, epoxies, resins and patients with a high suspicion of metal allergy, and such patients acrylics, organic dyes, plants, foods, medications, biocides, and demonstrate improved outcomes. This testing is not recom- germicides. The most common causes of plant dermatitis in mended for patients without such a history of metal sensitivity. outdoor workers include poison ivy, poison oak, and poison There is no information regarding pre-operative PT in patients sumac. Patch testing is not recommended to poison ivy because with a prior history of methacrylate or antibiotic sensitivity. it can cause sensitization or large bullous reactions. The clinician should recognize that contact sensitization to Accepted and validated criteria such as those proposed by metals or bone cement that are used in orthopedic, cardiac, Mathias should be used to confirm the diagnosis of OCD. These dental, and gynecological implants have been associated with include (1) the clinical appearance that is consistent with CD; (2) both dermatitis and noncutaneous complications. These com- potential culprit cutaneous irritants and/or allergens are present plications may include localized pain, swelling, erythema, in the workplace; (3) the anatomic distribution of dermatitis is warmth, implant loosening, decreased range of motion, stent consistent with workplace skin exposure; (4) the temporal rela- stenosis, and pericardial effusions in the case of cardiac implants. tionship between exposure and onset of symptoms is consistent Patch testing to implant or device components is recommended with CD; (5) nonoccupational exposures are excluded as prob- to help determine the etiology of the postimplantation adverse able causes of the dermatitis; (6) the dermatitis improves when reaction. absent from work exposure, and re-exposure results in exacer- Patients who experienced failed joint replacements and un- bation; and (7) PT performed according to established guidelines derwent revision using components dictated by a positive metal demonstrates positive and relevant reactions. PT reported resolution of their joint symptoms, most frequently Management of CD begins with avoidance of contact with the joint pain, joint loosening, and localized dermatitis. Those pa- confirmed offending agent and the patient is informed of any tients with a positive metal PT who were not revised continued cross-reactivity concerns. The identification and avoidance of J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S9 VOLUME 3, NUMBER 3S contact with the offending agent(s) is the key to successful lymphohistiocytic infiltrates. Features on physical examination or treatment of ICD and ACD. For cosmetic products, the patients histological findings are unable to differentiate ACD from ICD. should be given not only a list of what they are allergic to but also Patch testing and environmental history of exposure to contact a list of products that they can use, that are free of the suspected allergens is required. There are other dermatological conditions allergens. Several databases are currently available in the United that may resemble the clinical and/or histological appearance of States. CD, and these should be considered in the differential diagnosis Components of medical management of ACD include TCS (Table I)1,2 that includes cutaneous T-cell lymphoma. The with second line therapies including phototherapy, oral retinoids, cutaneous biopsy, if needed to differentiate CD from other forms and immunosuppression. TCS are widely accepted as the treat- of dermatitis, should be interpreted by a pathologist with ment of acute and chronic dermatitis, and selection of the TCS expertise in dermatopathology. for efficacy, potency, and acceptability is determined by many Summary Statement 2: In patients suspected of ACD, factors including the severity, the location, and the acuteness of patch testing is the gold standard to confirm the diagnosis. the dermatitis. Key to the management of ACD is still the [Strength of Recommendation: Strong; C Evidence] identification and avoidance of the allergen. Several topical T-cell The suspicion of ACD is the first step in making the diag- selective inhibitors (topical tacrolimus and pimecrolimus) have nosis. Patch testing is indicated in any patient with acute or been used successfully in the treatment of AD, but their efficacy chronic, often pruritic, dermatitis if underlying or secondary in ACD or ICD has not been established. Other treatments ACD is suspected. The history is important for the diagnosis and including cyclosporin, azathioprine and psoralen plus ultraviolet subsequent management of this disease. Although medical his- A (UVA) have been used for steroid-resistant ACD such as tory can strongly suggest the cause of ACD, it has moderate chronic hand dermatitis. sensitivity (76%) and specificity (76%) in establishing the Primary prevention of ICD and ACD involves avoidance of diagnosis.3 Because the patient may be unaware of any relevant exposure to possible irritants and allergens and appropriate skin exposure, virtually any eczematous lesion could be aggravated by protection. Avoidance of exposure may be accomplished by several a contact sensitizer.4-8 Noneczematous eruptions such a prurigo means including elimination of an irritant or an allergen, substi- nodularis may also be associated with clinically relevant positive tution, training, and rotation of job task. The use of personal PT.9 Studies have demonstrated the utility of patch testing in protective equipment such as gloves, goggles and/or face shields, children with chronic dermatitis.10 uniforms, and equipment to protect the skin from the exposure is The sensitivity and specificity of patch testing varies according important. The use of cotton liners under gloves can be useful. Skin to the allergen. For example, it has been reported that a positive care to protect the barrier function of the skin is important and PT to nickel sulfate is demonstrable in only 60% of patients with a involves the use of moisturizers, particularly lipid-rich moisturizers. positive history of nickel allergy (ie, positive predictive value 60%), In a review of 15 studies reporting prognosis in OCD between whereas 12.5% to 15% of persons reporting a negative history of 1958 and 2002, the range of complete clearance of the dermatitis metal allergy had a positive PT response to nickel sulfate.3,11 was 18% to 72%. Atopic dermatitis is associated with poorer Patch testing identifies contact sensitizers in nearly 50% of outcomes. The longer the duration between the onset and patients presenting with scattered generalized dermatitis.12 The diagnosis of hand dermatitis, the poorer the outcome. There is experienced clinician can misclassify ACD as nonspecific eczema significant job disruption for workers with CD. There are a small or IgE-mediated CU if the assessment is based solely on the percentage of individuals with occupational hand dermatitis who medical history without patch testing.13,14 do poorly even with removal from exposure. Although sensitization occurring after patch testing is rare, this has been reported after testing to plant allergens such as poison ivy or poison oak, as well as to p-aminoazobenzene, p-phenyl- CONTACT DERMATITIS: A PRACTICE enediamine, diaminodiphenylmethane, cobalt, chromium,15 and PARAMETEReUPDATE 2015 beryllium.16 The possibility of active sensitization can be mini- Clinical evaluation mized by testing with dilute solutions.17 Summary Statement 1: Consider ACD in the differential Patch testing has been shown to be cost effective if performed diagnosis of patients with chronic eczematous or non- early in the course of the disease in patients with chronic ACD eczematous dermatitis. [Strength of Recommendation: by reducing prediagnosis costs of treatment. Treated patients Strong; C Evidence] with CD confirmed by patch testing exhibit significantly greater Contact dermatitis may be suspected on the basis of the improvement in dermatology-specific quality of life than those clinical appearance of the lesions, the distribution of the patients who were not patch tested.18 Skin prick testing has no dermatitis, and the absence of other etiologies or lack of associ- role in the evaluation of ACD but is often useful in patients ated systemic manifestations. Acute CD is characterized by presenting with allergic CU. erythematous papules, vesicles, and crusted lesions. Recurrent or Summary Statement 3: In addition to personal products persistent episodes of CD will change over time from acute skin used by a patient suspected of ACD, review the home and inflammation to skin thickening, hardening, scaling, and workplace for other sources of contact allergens. [Strength of fissuring, with exaggeration of the normal markings known as Recommendation: Moderate; D Evidence] lichenification. Pruritus is characteristic of both acute and Work and environmental history must be carefully reviewed. chronic CDs, and constant skin rubbing contributes to the Chronologic exposure histories that include hobbies and spe- lichenification. Histologically, CD demonstrates intercellular cific activities relative to onset of the dermatitis should be edema of the epidermis known as spongiosis, with varying de- obtained. grees of acanthosis (thickening of the epidermal stratum basale The exact nature of the work duration of each activity and and stratum spinosum) and superficial perivascular, occurrence of similar skin effects in coworkers may provide clues S10 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015
TABLE I. Differential diagnosis of allergic contact dermatitis (ACD) Dermatologic condition Differentiating features and clues to diagnosis Irritant contact dermatitis Glazed, parched, or scalded appearance Sharply circumscribed dermatitis Healing begins promptly on withdrawal of the offending agent Patch testing negative Atopic dermatitis Personal or family history of atopy Early age of onset Chronic and recurrent Dry, scaly very pruritic Typical distribution Facial in infancy Extensors in early childhood Flexural areas in adolescence and adults Seborrheic dermatitis Distribution: areas with sebaceous glands Scalp, periauricular, face (medial eyebrows, glabella, nasolabial folds), presternal trunk, interscapular Blepharitis common Dandruff appears to be a precursor Distinctive morphology: dull, yellowish-red, sharply demarcated lesions covered with greasy-looking scales Dyshidrotic eczema Small (1-2 mm) vesicles, deep seated on nonerythematous base Palms, soles, and/or lateral aspects of fingers, often symmetrical Intensely pruritic and itching prodrome Persists for 2-3 weeks and then resolves by involution and desquamation Psoriasis Plaques typically have dry, thin, silvery-white, or micaceous scale Auspitz sign: removing scale reveals a smooth, red, glossy membrane with tiny punctate bleeding Dermatitis herpetiformis Genetic predisposition for gluten sensitivity Intensely pruritic Symmetrically grouped (herpetiform) papules and vesicles Elbows, knees, buttocks, scapula, scalp Direct immunofluorescence of the skin shows granular IgA at dermal papillae and occasionally along the dermo-epidermal border Mycoses fungoides and Patches with thin, wrinkled quality, often with reticulated pigmentation cutaneous T-cell lymphoma Pruritus varies from minimal or absent to common in premycotic phase and may precede MF by years Often on lower trunk and buttocks Cutaneous biopsy required for confirmation
as to potential causes of work-related ICD or ACD.19,20 Relevant not apply. Simultaneous exposure to both an irritant and a contact changes in work environments that result in new direct chemical allergen or 2 contact allergens can reduce the clinical threshold exposures to the skin, including vapors and fumes, must be concentration for elicitation of response to a given allergen. The 2 probed. Certain occupations (eg, hospital workers) require mechanisms have been suggested to explain the effect of exposure to frequent hand washing, and the use of cleansing agents may an irritant on potentiation of contact sensitization, including effects compromise the skin barrier and cause irritant hand dermatitis.21 on the immune response by upregulation of proinflammatory Because the worker may be unaware of specific chemicals to cytokines and/or enhanced penetration of the allergen.23 which he or she is exposed, MSDS obtained from the manu- Detergents are common causes of hand dermatitis because of facturer may be helpful; however, key sensitizing ingredients their disruption of the skin barrier and are frequently associated found at low concentrations are often omitted from product with ICD of the hand. Although there are some reports of ACD descriptions.22 related to detergents, careful evaluation suggests that allergic re- Hobbies and nonwork activity such as gardening, macramé, sponses are rare.24 Irritants that disrupt the skin barrier may then painting, ceramic work, carpentry, and photography may be penetrate into the epidermis resulting in injury to the keratino- sources of exposure to culprit contactants. Obtaining a detailed cyte membranes and release of inflammatory cytokines, and history of animal and animal product exposure is essential. contribute to developing ICD. This disruption of the skin barrier Summary Statement 4: Evaluate patients for both irritant and also allows for allergen penetration and resultant induction of allergic causes, especially in those presenting with hand immunological responses.25 dermatitis. [Strength of Recommendation: Strong; C Evidence] In addition to exposure to a single agent, simultaneous exposure to Physical examination multiple irritants and contact allergens may produce additive, syn- Summary Statement 5: Allergic CD should be suspected ergistic, or antagonistic responses. Although most research related and evaluated in the patient with both generalized and to irritant and allergic effects comes from studies of single agents, anatomically localized skin eruptions (such as the hands, individuals are often exposed to multiple irritants and allergens. In face, eyelids) that come in contact with the substances in the some situations, accepted threshold concentrations for elicitation of environment. [Strength of Recommendation: Moderate; C an allergic cutaneous PT response to a specific contact allergen may Evidence] J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S11 VOLUME 3, NUMBER 3S
The latest NACDG lists the top 3 most common body lo- lip dermatitis and 85% of these cases were women.34 Allergic cations of CD as scattered and/or generalized distribution, the contact cheilitis (ACC) often involves the lip vermillion border hands and the face.26 In addition, attention should be given to and extends to contiguous skin presenting with concomitant specific anatomical sites, particularly the face, eyelids, lips, oral perioral dermatitis; with adjacent oral mucosa typically spared. In mucosa, neck and scalp, hand, axillae, anogenital area, feet, and patients presenting to dermatologists with cheilitis, history lower extremities. Each of these areas can be affected by ACD combined with patch testing was able to confirm ACC in only and will be described in greater detail in Summary statements 6 34% to 38% of patients.34,35 FM, BOP, and nickel were the through 14. A diagnosis of ACD based on the physical exami- most common positive allergens on PT. Sources of fragrances nation and history alone, however, is not conclusive and should include oral hygiene products (eg, toothpastes, mouthwashes, be confirmed by PT.27 flavorings, compounds used for dental impressions), cosmetics, Summary Statement 6: In a patient with a facial rash and lip products (including lipsticks, glosses, and lip balms). In involving the periorbital areas (eg, eyelids), evaluate for ACD another study, lipsticks and lip balms were identified as the most caused by components of cosmetics, such as fragrances, pre- common sources of allergens for ACC in females and toothpaste servatives, and excipients, because these are common sensi- was the most commonly implicated allergen35 in males. In tizers of the facial skin. [Strength of Recommendation: toothpastes, flavoring chemicals are most frequent relevant al- Moderate; C Evidence] lergens, including mint derivatives such as spearmint, menthol, Facial ACD may present as a generalized facial eruption or in peppermint, carvone as well as cinnamal, and anethole.36 In lip specific regions such as the forehead, periorbital, or perioral areas. balms, propolis produced by bees, lanolin, coconut oil, almond Sensitizers in commercial facial products that are in direct skin oil, peppermint oil, and vitamin E are potential sensitizers.37 Less contact are the most common causes of facial ACD.28 Facial common antigen sources of ACC are jewelry (ie, nickel by ACD may also occur when contact allergens are transferred ectopic transfer) and topical medications (eg, neomycin, bude- ectopically to the face by the hands from other regions of the sonide, tetracaine). Interestingly, relevant positive PT to allergens body. Skin exposure to airborne plant-derived aeroallergens (eg, that were not part of the NACDG patch series have been tree, weed pollens) may cause an eczematous dermatitis of the identified in 36% of patients with ACC.34 This suggests that a exposed areas of the face, neck, and arms. These reactions typi- selected panel should be used that is based on the patient’s cally occur on a seasonal basis during the summer months.29 personal products. Compositae sensitizers are also found in many “natural” cosmetic Summary Statement 8: Evaluate patients with chronic oral products and may cause facial ACD. mucosal inflammatory conditions for disorders other than Allergic CD is the most common cause of isolated periorbital ACD. [Strength of Recommendation: Moderate; C Evidence] and eyelid dermatitis.28 Risk factors include female gender, AD, ACD is often considered in the differential diagnosis of and age over 40 years. In one study, the most common sources burning mouth syndrome, lichenoid tissue reactions, stomatitis, of causative allergens were found in cosmetic products (eg, gingivitis, orofacial granulomatosis, recurrent aphthous stomati- facial cream, eye shadow) and ophthalmic therapeutics. The tis, precancerous and cancerous lesions, viral and fungal in- most commonly identified sensitizers were FM (19%), BOP fections, lichen planus, especially in human immunodeficiency (10%), thimerosal (10%), and neomycin sulfate (8%).28 Nickel virus-infected patients and those with Melkersson-Rosenthal has also been identified as a very common sensitizer associated syndrome. Nevertheless, the oral mucosa is considered an im- with periorbital CD.30 Although it has been suggested that mune privileged site and oral contact sensitization is considered preservatives in topical ophthalmic medications are important to be uncommon. Persistent oral complaints or gingivitis has sensitizers, benzalkonium chloride (the most frequently used been associated with positive PT to allergens in dental compo- today) has not been found to be a common sensitizer in patients nents including mercury, methacrylate, and beryllium.38 with periorbital CD.31 Thimerosal, a possible sensitizer, is less In a large study of 331 patients presenting with oral symp- commonly used in ophthalmic products. A recent retrospective toms, PT was conducted to a comprehensive panel of flavorings, North American study of patients evaluated for periorbital preservatives, acrylates, medications, and metals.39 The mean age dermatitis could not detect significant sensitizers related to in this study was 58 years and 81% were women. The most ophthalmic products, and found that nickel and fragrances were frequent positive PT was to potassium dicyanoaurate, nickel, still the most common sensitizers identified by PT.32 ACD is gold sodium thiosulfate, FM, BOP, beryllium, cobalt, and responsible for 81% of cases of eyelid dermatitis. Common acrylate. More than 50% of patients presenting with burning sensitizers included nail product chemicals (tosylamide and/or mouth syndrome, lichenoid tissue reaction, cheilitis, stomatitis, formaldehyde resin, acyrlates), botanicals in personal care and gingivitis exhibited at least one positive reaction considered products, and nickel.33 to be relevant by the reporting physician. However, the term Summary Statement 7: Evaluate patients presenting with “relevant positive” PT used in large retrospective PT studies is lip dermatitis (cheilitis) and perioral dermatitis for both severely limited due to the lack of documentation of clinical irritant and allergic causes of contact dermatitis. [Strength of improvement following avoidance to the suspected “relevant” Recommendation: Moderate; C Evidence] allergens. Thus, based on available clinical data, there is insuffi- Eczematous cheilitis is an acute or chronic inflammation of cient evidence to confirm a causative role of contact allergy in the the lips and is characterized by itching, burning, redness, edema, aforementioned oral syndromes. and fissuring. This is most commonly caused by physical (eg, Chemical and traumatic injury may be the most common cold, dryness, wind) or chemical irritants (saliva, lip cosmetics, or causes of contact reactions involving mucous membranes. Many other oral products). Other causes include atopic cheilitis that is of these reactions are caused by caustic chemical agents inad- observed in patients with AD. In a series of more than 10,000 vertently applied during dental treatment. Lastly, one should be patients reported by the NACDG, 2% of patients presented with aware that oral erosions and blistering lesions may be the initial S12 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015 presenting symptoms of autoimmune blistering diseases such as Summary Statement 11: Evaluate patients with axillary pemphigus. dermatitis for ACD caused by local contact sensitivity to al- Summary Statement 9: In patients presenting with lergens in topically applied products found in deodorants dermatitis that involves the scalp and neck, consider patch and textiles. In some cases, axillary dermatitis could be a testing for common causative sensitizers in cosmetics, hair manifestation of SCD (ie, “the baboon syndrome”). products, and jewelry. [Strength of Recommendation: Mod- [Strength of Recommendation: Moderate; C Evidence] erate; C Evidence] ACD involving the axillary region is often due to contact Nickel remains the most common contact sensitizer and is sensitivity to fragrance chemicals in deodorants, including found more frequently in women than it is in men. The gender hydroxyisohexyl-3-cyclohexene carboxaldehyde, isoeugenol, difference is likely due to greater exposure of the neck, hands and hydroxycitronellal, as well as cinnamic aldehyde and sensitizers in ears to nickel in jewelry,40,41 as well as piercing practices. natural botanical deodorants.47-52 Although ICD is more com- Females are twice as likely as males to have ACD involving the mon, ACD has been rarely attributed to antiperspirants.53 Iso- head and neck due to cosmetics.42 Among patients with cosmetic lated case reports of ACD causing axillary dermatitis have been allergies, fragrances, preservatives, and emulsifiers are the most attributed to propantheline bromide used as a treatment for common causative allergens. Specifically the most common in hyperhidrosis.54 Pretesting with a ROAT on the flexor surface of both genders are quaternium-15, FM and BOP. PPD (hair dye), the forearm and axilla is advised in any patient with a history of a glyceryl thioglycolate (permanent wave solutions), tosylamide pre-existing axillary dermatitis before initiating use of a new and/or formaldehyde resin (nail enamel products), and methyl product. methacrylate (nail product adhesive) were common sensitizers in ACD due to disperse dyes in clothing can elicit eczematous females. Sensitizers in hair care products affect 30% of females eruptions in the axillae, feet, and groin.55 In Sweden, 1.5% of all and 22% of male patients who were evaluated for CD.42 In patients undergoing patch testing has positive reactions to a addition to the most common hair dye sensitizer, PPD, more textile dye mix and the most common reactive dye was disperse than 20 other potential sensitizers have been identified in hair orange 1, whereas a clinic in North America reported that dye products.43 Frequent sensitizers contained in shampoos disperse blue 106 and disperse blue 124 were the most frequent include fragrances, CAPB (a surfactant), preservatives such as sensitizers.56 Patients reacting to a textile dye mix more often MCI/MI, and preservatives that are formaldehyde releasers (eg, reported dermatitis involving the axillary folds, arms, face, and quaternium-15, imidazolidinyl urea). Other ingredients that are neck.57 In the axillae, the periphery is more often involved than potential sensitizers include propylene glycol, vitamin E, para- the axillary vault due to greater contact of the garment to the skin bens, benzophenones, iodopropynyl butylcarbamate, and meth- in this area. yldibromo glutaronitrile/phenoxyethanol.44 Allergic CD Axillary dermatitis may be a manifestation of SCD, specifically involving the scalp is most frequently caused by sensitization to the “baboon syndrome”, a diffuse eruption involving flexural and medical products (eg, neomycin, benzocaine), hair tint, dyes, hair intertriginous areas following oral, intravenous, or trans- cleansing products, and bleaches.45 cutaneous exposure to the allergen in a contact-sensitized indi- Summary Statement 10: Consider irritant and ACD in all vidual.58 Allergens associated with SCD are listed in Appendix C. patients presenting with acute or chronic hand eczema. All Summary Statement 12: Evaluate patients presenting with such patients suspected of CD should undergo patch testing. anogenital dermatitis for possible ACD to antigens contained [Strength of Recommendation: Moderate; C Evidence] in topically applied products. [Strength of Recommendation: Allergic contact sensitization is a common cause of chronic Moderate; C Evidence] hand dermatitis. The prevalence of ACD in patients pre- Allergic CD can cause anogenital dermatitis. A total of 17% to senting with hand dermatitis or hand eczema varies according 74% of patients presenting with anogenital dermatoses have been to exposure history and occupation. Hair dressers presenting diagnosed with confirmed ACD to allergens contained in topi- with hand dermatitis had a high prevalence of ACD (75%) cally applied products such as cosmetics, medications, and with 25% of the remaining cases being attributed to irri- feminine hygiene and contraceptive products. In a recent large tants.40 In a multicenter collaborative study in Denmark, 508 retrospective study, 44% of patients with anogenital dermatitis consecutive patients who presented with hand eczema were (including 41% of women and 50% of men) were identified with evaluated. In these patients, ICD was diagnosed in 38%, ACD ACD. The most common sources of antigens were topical in 24%, AD in 19%, and in 22%, nonspecific dermatitis was medications, including TCS, fragrances, BOP, nickel sulfate, the diagnosis.46 Even in children, ACD is a common cause of cinnamic aldehyde, and neomycin sulfate. Cinnamic aldehyde, hand dermatitis with one study reporting as high as 36% dibucaine, benzocaine, hydrocortisone-17-butyrate, and bude- prevalence. Sensitizers deemed relevant to ACD involving the sonide were more common sensitizers in patients presenting hands included the preservative quaternium-15 (16.5%), exclusively with anogenital dermatitis. A total of 21% patients formaldehyde (13.0%), nickel sulfate (12.2%), FM (11.3%), were diagnosed with ICD; the most common irritants were thiuram mix (10.2%), BOP (9.6%), carba mix (7.8%) used in cosmetics, soaps and cleansers, various health aides, and un- rubber products, neomycin sulfate (7.7%), bacitracin (7.4%), known agents.59 In another patient series, the preservative MI and methyldibromo glutaronitrile/phenoxyethanol 2.0% and benzocaine were frequently identified as contact allergens in (7.4%). Thus, it is strongly recommended to evaluate all pa- patients with anogenital complaints.60 Methylisothiazolinone, tients with chronic hand eczema for ACD by obtaining a used as a preservative in wet baby wipes has been identified as a medical history of contact allergy and performing patch sensitizer and cause of ACD involving the buttocks and perianal testing. In addition to ACD, chronic hand eczema may be a area in children.61 presenting symptom of psoriasis and should be considered in Summary Statement 13: Consider a diagnosis of SCD the differential diagnosis. following systemic exposure (eg, ingestion, infusion, or J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S13 VOLUME 3, NUMBER 3S transcutaneous exposure) to a known contact sensitizer in a topical preparations containing fragrances and antiseptics should patient who presents with generalized dermatitis, inter- be avoided in patients with leg ulcers and that they have the triginous and flexural exanthema (Baboon syndrome), and/or potential to become sensitized to components of products and a flare at previous cutaneous sites of exposure. [Strength of medications that are used to treat leg ulcers.70 Recommendation: Moderate; C Evidence] Summary Statement 15: In addition to avoiding irritants The most common causes of SCD consist of 3 groups of al- in patients with AD, evaluate for ACD if suspected, as the 2 lergens: (i) metals such as mercury, nickel, and gold; (ii) medica- dermatologic conditions often coexist in the same patient. tions including aminoglycoside antibacterials, CS, and [Strength of Recommendation: Moderate; C Evidence] aminophylline; and (iii) plants and herbal products including the There is conflicting evidence as to whether patients with AD Compositae and Anacardiaceae plant families and BOP.58 Nickel are at heightened overall risk of contact sensitization compared sulfate is ubiquitous in steel devices, jewelry, clothing, and food. with nonatopic individuals. One recent study showed an inverse Systemic CD can result from ingestion of trace amounts of nickel relationship between contact sensitization and severe AD.73 in soy, chocolate, nuts, green beans, peas, and canned foods.62 Because AD is associated with an impaired skin barrier, it is Other examples of systemic exposure to allergens that can trigger plausible that this impairment is likely to increase absorption of diffuse SCD include systemic administration of aminoglycoside topically applied chemicals and enhance the risk of subsequent antibiotics in a patient sensitized to topical neomycin; hydroxyzine sensitization. Atopic dermatitis has been diagnosed in 34% of ingestion or administration of IV aminophylline in patients with children with clinically relevant PT reactions, although children ACD to ethylenediamine, which cross-reacts with both medica- without AD are equally as likely as those with AD to exhibit tions; oral estrogen triggering a systemic dermatitis after sensiti- clinically relevant positive PT.74 zation to estrogen patches63;orflare of previously positive In a large population-based study of Danish adults, contact budesonide PT sites after inhalation of nebulized budesonide.64 It sensitization to at least one allergen was observed in 14% of is postulated that once the allergen has entered the blood stream, it patients who self-reported AD, whereas in 10% of those without encounters and reactivates specific memory T cells that then home AD had ACD. This overall difference between atopics and to the site of the previous dermatitis. nonatopics in this study was primarily attributed to a higher Patients may also experience SCD after oral challenges with frequency of allergy to fragrances that may reflect a greater cu- fragrance-containing foods, Chinese herbs, or drugs. Patients mulative skin exposure to topical treatments containing fra- who are contact sensitive to BOP are prone to SCD with grances.73 In this same study, the risks associated with filaggrin ingestion of foods or flavoring agents that are constituents of mutations were also evaluated. Self-reported hand dermatitis as BOP (eg, citrus products, ice cream, cinnamon, chutney, cola, well as AD combined with hand dermatitis was significantly vanilla, curry, ketchup, or tomatoes) or cross-react with those associated with contact sensitization in patients with a filaggrin constituent allergens. In addition, various spices, garlic, cashew gene mutation (R501X, 2282del4), whereas AD alone combined nuts, and proteinaceous substances handled by grocers, meat and with filaggrin mutations but without hand dermatitis was not fish handlers, and bakers have been cited as causes of SCD. significantly associated with contact sensitization.75 In a North Summary Statement 14: Consider PT to rubber chemicals, American study, PT results compared between 300 patients with adhesives, and leather components of footwear in patients AD and approximately 3000 patients without AD found that presenting with unexplained chronic dermatitis involving the patients with AD were significantly more likely to exhibit contact lower extremities, feet and/or soles. [Strength of Recom- sensitization and this difference was attributable to sensitization mendation: Moderate; C Evidence] to metals.76 The pattern of foot dermatitis due to ACD varies according to In a report by Jacob et al,77 comprehensive PT played a key the type of footwear used. ACD rarely localizes between the toes role in the identification of relevant chemical allergens in per- and typical sole involvement spares the instep and the toe’s sonal hygiene products and topical treatments used in manage- flexural creases. Patch testing studies have identified p-tertiary ment of 3 children with severe, recalcitrant AD. Avoidance of butylphenol formaldehyde resin (in adhesives), potassium di- offending allergens resulted in marked improvement of eczema, chromate, cobalt chloride, and carbamates as the most common which permitted reduction in TCS and subsequent discontinu- allergens.27,65-72 Allergic CD involving the feet is commonly ation of systemic immunosuppressive therapy. caused by sensitization to common rubber allergens (carbamates, thiurams, and mercaptobenzothiazole). Patients suspected of Patch testing recommendations rubber ACD should also be tested to mixed dialkyl thioureas Summary Statement 16: Avoid or reduce doses of immu- (diethylthiourea and dibutylthiourea) because the majority of nosuppressant medications such as systemic CS and other thiourea-sensitized patients do not react on PT to the more systemic immunosuppressants before patch testing. Avoid common rubber allergens.67 Children presenting with sole application of TCS, TCI, or ultraviolet radiation to the PT dermatitis should be evaluated by PT to rule out ACD caused by site, because these may reduce allergic PT responses. rubber additives or chromates (from leather tanning).68 All the [Strength of Recommendation: Moderate; C Evidence] aforementioned chemicals should be included in PT panels to The majority of adult patients treated with oral CS exceeding evaluate patients with foot dermatitis. 20 mg/day of prednisone or its equivalent have been shown to The vast majority of patients with chronic leg ulcers have diminish skin test reactivity at 48 hours to 5% nickel sulfate.78 positive PT to chemical sensitizers found in topically applied The effect of systemic CS on the results of PT is less understood preparations. The most common of sensitizers were BOP, FM I, for children. Patch tests in patients on low doses of prednisone antibacterial agents, CS, and lanolin.69,70 In a recent prospective and cyclosporine may still yield clinically relevant results.79 study of patients with leg ulcers, the number of positive PT There are no supporting data that guide the duration of ste- correlated with duration of the leg ulcers. This suggests that roid reduction or withdrawal before performing PT. The S14 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015 suppression is not absolute, and if necessary, PT should be A study of the T.R.U.E. Test (panel of 35 antigens and a performed while on the lowest possible dose of the immuno- negative control) (Appendix H) showed that it is highly repro- suppressant medication.79,80 If the clinical suspicion is high ducible with only a 5% discordance between concomitant despite a negative PT, consider repeat testing when the immu- duplicate tests in individual patients.89 Depending on the test nosuppressant doses are lowered or discontinued. antigen, the T.R.U.E. Test method has moderate concordance High/medium potency TCS (ie, betamethasone dipropi- with individually loaded chamber systems. In separate studies, onate 0.05%) applied topically to PT sites for 3 successive 62% to 63% overall positive concordance rates were reported days suppress 48-hour responses to contact allergens.81 The between the Finn chamber system and T.R.U.E. Test test site where the PTs are applied should have no topical methods.90,91 The T.R.U.E. Test is widely used because of its potent CS or TCI applied for 5 to 7 days before ease of application. However, it lacks flexibility and has currently testing.82,83 Topical tacrolimus (0.1%) pre-applied to skin a limited number of allergens available. The NACDG series test sites for 48 hours suppressed 48-hour PT responses to comprises 65-70 allergens and is used as a screening research tool 5% nickel sulfate.84 Pretreatment of skin test sites with UV to track trends in delayed-type contact sensitization. It also tests irradiation produced dose-related suppression of erythema established and newly marketed chemicals to determine preva- measured at 48 hours after application of nickel sulfate PT lence and relevance in causing ACD. Thus, the NACDG may in nickel-sensitized subjects.85 Protection from UV-induced contain allergens in different vehicles and concentrations. The immunosuppression of allergic responses to nickel sulfate ACDS has outlined a Core Allergen Series of suggested 80 al- was achieved by application of sunscreen products blocking lergens that can be scaled up or down depending on the needs of UVA and UVB wavelengths.86 the physician and the patient being tested. The allergens are Systemic antihistamines are generally not believed to interfere arranged with more likely allergens being higher in the tray. with the PT readings. A study showed that treatment with 10 mg Appendix I is an example of a PT form listing the NACDG loratadine for 4 days before patch testing was associated with a series. Exclusive reliance on the T.R.U.E. Test antigen panel as significant reduction in the size of the eczematous responses to opposed to an extended panel used by the NACDG or the nickel sulfate. Recently, desloratadine given for 4 days at twice standard series outlined by the ACDS and personal products can the normal daily dose (5 mg po bid) did not significantly impact miss detection of sensitization to clinically relevant antigens.26 interpretation of positive patch responses to 10 contact aller- Currently, there are different loading chambers available; how- gens.87 This would indicate that antihistamines do not need to ever, none have shown superiority over another. be withheld for PT. Summary Statement 19: Read and interpret PT conform- Summary Statement 17: In addition to using a core or ing to the scoring system developed by the International baseline series of PT allergens in evaluating ACD, consider Contact Dermatitis Research Group. [Strength of Recom- using supplemental series of PT allergens based on specific mendation: Moderate; D Evidence] patient exposures and the patient’s personal products, to Patch testing techniques and scoring reactions by a grading increase the probability of identifying relevant sensitizers. scale were first standardized in the 1930s. The International [Strength of Recommendation: Moderate; C Evidence] Contact Dermatitis Research Group published the following Reliance on a core or baseline series of PT antigens such as nonlinear, descriptive grading scale in 1970,92 which continues those used by the NACDG or in the T.R.U.E. Test panel for to be widely used. assessing all patients is likely to lead to underdiagnoses of ACD. A (-) Negative reaction recent multicenter North American study of over 4300 patients (?þ) Doubtful reaction with faint erythema only published in 2013 revealed that 25% of patients exhibited a (1þ) Weak positive reaction with nonvesicular erythema, clinically relevant positive test to an antigen not included in a infiltration, possibly papules standard 70-antigen panel, and 25% reacted to an allergen that (2þ) Strong positive reaction with vesicular erythema, infil- was not part of the T.R.U.E. TEST panel.26 In 2009, the tration, and papules NACDG reported that 23% of 4454 patients in a multicenter (3þ) Extreme positive reaction with intense erythema and study exhibited at least one relevant positive test to a supple- infiltration, coalescing vesicles, bullous reaction mentary allergen and 5% reacted to a clinically relevant occupa- (IR) Irritant reaction tional allergen not part of the standardized panel of 65.88 Many (NT) Not tested PT companies provide kits with allergen panels selected for a The details of this rating system and corresponding clinical specific industry such as machinists, cosmetologists, or dental interpretation with a visual key are given in Appendix H and workers (Appendix D). There are other standardized panels for Figure 1. exposure groups such as cosmetics, textiles, plastics, and glues Summary Statement 20: Remove and read PT at approx- (Appendix E), and medications and topical treatments (Appendix imately 48 hours after application. A second reading should F). Currently, such kits can only be obtained from the manufac- be done between 3 and 7 days following application. turers listed in Appendix G. Frequently, especially in the eyelid, [Strength of Recommendation: Moderate; C Evidence] lip, and facial dermatitis, it may be necessary to include personal In the evaluation of delayed hypersensitivity reactions, the products and substances specific to the patient’sexposurehistory. initial reading of PT should be done approximately 48 hours Summary Statement 18: Patch testing can be performed after their application following patch removal.93 However, if either using a preloaded thin-layer rapid use epicutaneous CU is considered, the PT has to be checked at 20-30 minutes testing kit of 36 chambers or with a panel of antigens loaded after application. Tests may need to be read 30 minutes after individually in a chamber system recommended by the removal of the patches to allow erythema from the occluding NACDG Research Group or the ACDS. [Strength of pressure or stripping of the tape and/or chamber to resolve. A Recommendation: Moderate; C Evidence] second reading must be done, usually between day 3 and day 7 J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S15 VOLUME 3, NUMBER 3S
allergens dissipated after the day 5 reading.96 With most al- lergens, however, the gain in positive reactions was biggest when a reading was performed at day 5.95,97 Table II lists al- lergens with typical early and late reactivity. Reactions occur- ring even as late as days 10 to 14 may be due to a delayed irritant response and delayed allergic reactions such as for metals and TCS, and very rarely represent sensitization from the PT.97-99 Conversely, some irritant reactions appearing within the first 48 hours tend to disappear (decrescendo effect) by 96 hours.100 In rare situations where patient circumstances (ie, distance from the practice, insurance issues) do not permit 3 visits, the patches can be removed by the patient or local physician at 48 hours and read by the treating physician in 72- 96 hours. Patients can be instructed to take a picture of the back before removing the patch (to help the clinician determine the integrity of the PT system, and to record any nonadherent or loose patches), and another picture after removing the patch. They should also re-label the PT sites after removal. However, this approach is considered suboptimal. Summary Statement 21: Consider that a possible false- positive reaction can result with the use of irritants or allergic substances at potentially irritating higher concentrations, pressure reaction from the filling chamber, an “angry back syndrome,” or patch testing on skin with active dermatitis. [Strength of Recommendation: Moderate; D Evidence] Many variables contribute to the strength of the PT reaction, including the concentration and potency of the allergen, the de- gree of subject sensitization, the length of application time, and the timing of the readings.103 The greatest source of misinter- pretation is due to questionable or irreproducible reactions in the doubtful (?þ) or weakly positive (1þ) categories. The timing of the response may also affect its clinical significance; for example, a weak reaction at day 7 is more likely to be clinically relevant than one at day 3. The inability to separate nonspecific from true allergic responses may be encountered in patients who exhibit the “angry back” or “excited skin” syndrome, which is defined as false- positive reactions adjacent to large true-positive reactions that induce contiguous skin inflammation and irritability. The longer the duration of the primary dermatitis, the greater the risk for the excited skin syndrome to occur with patch testing.104 This should be suspected in cases with more than 5 reactions in close proximity to each other. The underlying mechanisms are not fully understood. A pustular patch reaction should not be misinterpreted as a FIGURE 1. Visual key for scoring patch test reactions. positive reaction in PT. A pustular reaction is common in atopic individuals and in response to test of metals such as nickel, copper, arsenic, and mercuric chloride. The test site is only after the initial application.94 Occasionally, an additional late minimally pruritic and this type of pustular reaction is frequently reading after 7 days may be needed for certain contactants such an irritant reaction. as metals, some antibiotics, and TCS that may yield late re- The position of the allergen in a multiple allergen template actions.95 A collaborative study documented that approximately may give rise to the false-positive results, especially if cross- 30% of relevant allergens that were negative at the 48-hour reacting or co-sensitizing substances are tested in too close reading became positive at a 96-hour reading, suggesting that 96 proximity.105 Marginally irritating allergens may also trigger hours may be optimal for a second reading. Consider a late false-positive reactions.106 Repeat the PT with greater separation reading for allergens with negative early reactions, when the of allergens or sequentially if the initial reactions are not clinically clinical history strongly supports sensitization. Four allergens relevant, because false-positive reactions are not reproducible with the highest frequencies of delayed-positive reactions were when the triggering allergens are removed.106 gold sodium thiosulfate 0.5% (delayed-positive reactions in 22/ Summary Statement 22: Recognize the possibility that 353 patients), dodecyl gallate 0.25% (6/105), palladium chlo- false-negative reactions could be due to inadequate allergen ride 2% (8/194), and neomycin sulfate 20% (10/253). In concentration needed to elicit a response; inability of the contrast, reactions to certain preservatives and fragrance vehicle to release sufficient allergen; reduced skin S16 FONACIER ET AL J ALLERGY CLIN IMMUNOL PRACT MAY/JUNE 2015
TABLE II. Allergens associated with early and late reactions wrong carrier vehicle that resulted in insufficient penetration of Allergens associated with early peak reactions (at 48 h) the allergen, or inclusion of the wrong salt or version of the allergen. UV sunlight (eg, tanning), TCS, and TCI on the area of Myroxylon pereirae 95,101,102 Balsam of Peru resin ( ) PT and systemic CS (ie, >20 mg/day prednisone)78 and other Benzoyl peroxide102 102 immunosuppressives can all inhibit a positive patch response. Carba mix Also, the patient may need photo-patch testing if photo-allergic 102 Cinnamic alcohol CD is suspected. 95 Cocamidopropyl betaine Summary Statement 23: Determine the relevance of a PT 95 Fragrance mix result based on the clinical and exposure history when Imidazolidinyl urea102 interpreting the PT. [Strength of Recommendation: Moder- Thiuram mix102 ate; D Evidence] Wool alcohols102 The clinical relevance of positive PT reactions to ACD can only
Allergens associated with reaction on day 5, resolved day 7 be established by carefully correlating the history, which includes exposure to the allergen, with the PT test results. A positive PT 101 Fragrance mix may be clinically relevant depending on current or past exposures. Methyl dibromo glutaronitrile phenoxy ethanol101 Current relevance is defined as definite if the PT or use test with Octyl gallate101 the suspected material is positive; probable if the antigen is present Balsam of Peru101 in known skin contactants and the clinical presentation is Benzalkonium chloride101 consistent with that exposure; or possible if skin contact with Benzoic acid101 materials known to contain the allergen was likely. Past relevance Disperse blue #124101 is considered if the PT is positive but the exposure was in the past, and not the present.109,110 Allergens associated with late peak reactions (days 6-7) Summary Statement 24: Consult physicians with expertise Dyes in patch testing to household cleaning or industrial products Para-phenylenediamine95,102 if testing to the actual product suspected of containing the Medications relevant allergen(s) is necessary, because false-positive and Neomycin95,101,102 severe irritant reactions can occur. [Strength of Recommen- Caine mix95 dation: Moderate; C Evidence] Topical corticosteroids Household and industrial products should only be tested by Tixocortol-21-pivalate95 physicians with expertise on this type of testing after determination Budesonide95,101 of safety from MSDS information and using nonirritating PT 111 Metals based on an authoritative text. Some of these chemicals can be Nickel sulfate95,101 extremely toxic to the skin and on rare occasions even produce Gold sodium thiosulfate101 systemic effects. The PT concentration of these products must be Palladium chloride101 based on established protocols when available. Nonirritant con- Potassium dichromate95 centrations are established by testing groups of unaffected volun- Cobalt chloride95 teer control subjects. Whenever possible, customized contactants should be incorporated into a petrolatum base, but in some in- Preservatives and glues stances, a different vehicle should be used to increase exposure to Dodecyl gallate101 the relevant antigen.112,113 It may be difficult to distinguish an p-Tert-butyl phenol formaldehyde resin95,102 irritant from an allergic reaction. Examples of direct PT to prod- Methylchloroisothiazolinone95 95 ucts at nonirritating concentrations found in Patch Testing 3rd Epoxy resin 112 102 Ed., are bath products 1% aqua, shampoo 5% aqua, synthetic Ethylenediamine dihydrochloride detergents 2% aqua, soap 1% or 2% aqua, and glues 1% to 20% 95,102 Mercapto mix in aqua, acetone, alcohol, or petrolatum. Antiperspirant, eau de 95,101,102 Thimerosol cologne, cosmetics that are leave on, and insect spray may be PT without dilution. Agents that should not be patch tested include benzene, toluene, and other solvents, such as gasoline, kerosene, responsiveness because of prior ultraviolet light exposure (ie, lime, floor wax and polish, diesel oil, rust removers, and others. sun, tanning bed); concomitant immunosuppressive thera- Furthermore, unknown substances should not be tested. pies; or methodological testing errors such as insufficient Summary Statement 25: Consult physicians with expertise occlusion, failure to perform delayed readings, and failure to in UV radiation and photo-patch testing to confirm a sus- perform a photo PT. [Strength of Recommendation: Mod- pected diagnosis of photo-allergic CD. [Strength of Recom- erate; C Evidence] mendation: Strong; C Evidence] The strength of the reaction on the skin does not necessarily Photo-patch testing should be done in clinical settings with the correlate with clinical relevance. For example, aminoglycosides expertise, materials, and equipment to perform the procedure. In may cause weak reactions on PT that are nonetheless clinically brief, duplicate applications of the suspected photo-sensitizer(s) are relevant.107 The frequency of false-negative results is not known, placed on either side of the upper back, and occluded for 24 to 48 but has been estimated to occur in up to 30% of patch-tested hours. A recent study suggests that 2 days of occlusion before patients.108 Potential causes of false-negative reactions include irradiation of allergens is more sensitive at detecting photo- too low a concentration of the allergen in the extract, use of the allergy.114 After PT removal, one side of the back is then irradiated J ALLERGY CLIN IMMUNOL PRACT FONACIER ET AL S17 VOLUME 3, NUMBER 3S