Be Prepared for Warm Weather Skin Conditions Expert tips for treating pediatric patients during the warm, sunny months.

Papular Urticaria from Bug Bites lines note that physicians sometimes second-guess Papular urticaria, the unique hypersensitivity reaction their diagnoses when parents immediately dismiss the to bites from bugs of various types, often go undiag- idea. If more people become more aware of papular nosed for a number of reasons, a recent study in urticaria, they will be less likely to question physi- Pediatrics has noted. To help physicians make the cor- cians, and the correct diagnosis is much more likely at rect differential diagnosis of this condition, Bernard the outset, Dr. Cohen explains. “Once parents are Cohen, MD, Director of Pediatric Dermatology at taught how to recognize the skin lesions by their prac- Johns Hopkins Children’s Center in Baltimore and titioners, three quarters of the problem would be Raquel Hernandez, MD offer the mnemonic, gone,” he says. SCRATCH (see Table). “Papular urticaria is quite common, people just Protection and Prevention often times don’t recognize it,” Dr. Cohen says. Future studies may explore new methods of protection “Without the right diagnosis, most people will have and prevention, Dr. Cohen suggests, adding that these recurrent and consistent lesions for a number of are areas about which little is currently known. Even years.” Some patients are eventually subjected to without exact knowledge of the offending organism, unnecessary studies in order to identify the cause of there are steps patients and parents can take to pro- the persistent, recurrent lesions. If physicians recog- vide protection and minimize bites. nize the SCRATCH principles, he says, this would min- An infestation must be eliminated, and any carriers imize the problem. must be treated. This means sanitizing clothing, bed- Treating papular urticaria resulting from bug bites ding, and other sources of infestation and treating pets can be very difficult, according to Dr. Cohen, since and other affected family members. there are no good treatments for the condition. Most Additionally, Dr. Cohen says, it helps to keep the people become sensitized when bitten by the same skin covered at night, which includes wearing long organism—usually fleas, mosquitoes or bedbugs; when pants and long sleeves that protect the skin and they get new bites, they have the same kind of hyper- decrease the number of bites. This is more crucial if sensitivity reaction, he notes. the patient is outdoors but may be helpful indoors, as “I’ve tried everything to treat it including low well. potency, mid potency, high potency topical It’s also important to urge parents to exercise cau- steroids, occlusive steroids, and intralesional tion when applying perfumes, colognes, lubricants, steroids,” he says, but none of these has worked hair products, and other skincare products to their particularly well. Therefore, he says, the emphasis children. These products often have fragrances in should shift from treatment to education and pre- them that attract bugs. vention. Insect repellents, such as DEET, can be used for The first step in management is helping parents to outdoor use. Parents can spray repellents on a child’s understand and accept the diagnosis. SCRATCH guide- clothes rather than directly to the skin.

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SCRATCH any lattitude. Along with , , candi- da , furunculosis, , and folliculi- Symmetry: Most patients present with a symmetric eruption; the tis, erythrasma has been reported to occur with most commonly affected areas tend to be exposed areas of the increased incidence among obese individuals3 and face, neck, arms, and legs, which contrasts with distribution found those with .1 However, the infection may also in scabies. be common among athletes, particularly when affect- Clusters: Characteristic of bedbug bites (sometimes seen in flea ing the toe webs.4 About 15 percent of cases occur in bites), these lesions are usually triangular groupings. children, with increasing incidence as individuals age into adolescence. “Rover” Not Necessary: Physicians find it difficult to diagnose papu- Among other cutaneous diseases, the differential lar urticaria when the patient has no history of a pet in the home, however, only a remote history of pet exposure is necessary to pro- diagnosis of erythrasma includes cutaneous fungal duce a rash. infections, including pityriasis rotunda, tinea cor- poris/cruris,5 tinea pedis, and pityriasis versicolor.6 Age: Authors stress that IBIH is most prevalent between the ages Importantly, erythrasma may coexist with dermato- of two and 10, which may help physicians narrow the differential phyte infections.7 Proper diagnosis of erythrasma and diagnoses. any concomitant (s) is essential for initia- Target Lesions/Time: Target lesions are characteristic for IBIH, espe- tion of appropriate therapy targeted at all causative cially in patients with darkly pigmented skin. “T” also stands for organisms. Topical anti-infective therapy, including time, emphasizing the chronic nature of the eruption and the need broad-spectrum ketoconazole, is typically sufficient to for patience on the part of the patient and the physicians. manage the condition, although systemic antibiotics Confusion: Sometimes parents may be confused by conflicting infor- have traditionally been advocated and may be indicat- mation or unaware of facts about infestations, leading them to reject ed for severe or refractive cases. the diagnosis of IBIH and the physician to doubt him/herself. Presentation and Prevalence Household: It is actually quite rare for multiple family members to Erythrasma is a bacterially mediated scaly skin erup- have similar symptoms of IBIH because individuals have different thresholds for being sensitized. tion typically localized to warm, moist skin folds. The rash tends to be deep red to brown in color and is not Finally, Dr. Cohen urges patients and clinicians to typically associated with significant pruritus. remember that insect bites can occur all year round, Erythrasma was once improperly considered a fungal depending on the insect. Parents and physicians may infection, though research over the past 50 years has think of bug bites only in the spring and summer confirmed the role of C. minutissimum in its pathogen- when temperatures are warm and children spend esis.8,9 These gram-positive bacteria are typically part more time outdoors. Dr. Cohen reminds that the of the normal resident flora of human skin. In 1965, above tips apply in fall and winter, as well. Montes, et al. evaluated biopsied skin from patients —Ted Pigeon, Senior Associate Editor with erythrasma absent any concomitant fungal etiolo- gy.8 They found C. minutissimum dispersed over the skin surface, between and penetrating superficial Recognize and Treat Erythrasma cornified cells, and within keratinized cells. Their Erythrasma is a frequently under-diagnosed cutaneous investigation showed that the stratum corneum of infection caused by minutissimum. It affected patients was hyperkeratotic, and identified commonly affects body folds, particularly the groin, likely keratolytic processes associated with the pres- and has been identified as one of the leading causes of ence of intracellular bacteria. interdigital foot infections.2 Traditionally, erythrasma Erythrasma generally is diagnosed through visualiza- has been considered to more frequently affect individ- tion, but it may be mistaken for candidiasis, intertrigo, uals living in warmer climates, though it can occur at , seborrheic dermatitis, contact dermatitis, or

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Sunburns generally benign condition, the use of systemic antibi- Multiple studies have attempted to identify a link between sun- otics as first-line therapy becomes questionable. burns in youth and the development of skin cancer as an adult. Topical antimicrobial therapies are second-line Consistently, the findings associate excess sun exposure with choices for erythrasma management.9 Topical antibiot- long-term risks. Jonathan Wolfe, MD, of Plymouth Meeting, PA, ic preparations have not been shown to be very effec- puts it simply. “Every time you get sunburned, you damage your tive for erythrasma in the published literature. skin cells and increase your risk of developing skin cancer,“ he However, antimicrobial ointment 2% has says, “Having multiple blistering sunburns as a child or teenager demonstrated efficacy, as has Whitfield's ointment increases your risk of developing skin cancer as an adult.” (salicylic acid and benzoic acid).1,9 Whitfield’s ointment Avoiding sunburns through the use of sun-smart strategies is reportedly has similar efficacy to systemic erythromy- ideal. If a sunburn does develop, the best treatment is non cin for erythrasma affecting the axillae and groin and 1 steroidal medications like ibuprofen, cool compresses, ice, plen- is superior to the oral agent in the interdigital areas. ty of fluids, and moisturizing creams, Dr. Wolfe says. “Significant Despite the potential efficacy of the topical antimi- blistering covering large surface areas become more concerning crobial ointment preparations, they are not ideal in the due to the risk of secondary infection and the possibility that clinical setting. They may lack cosmetic elegance and hydration status can become varriable.” thus be associated with low adherence. Most patients are unwilling to apply thick, greasy preparations to Dr. Wolfe also says that teens should be taught how to conduct intertriginous areas or toe webs. skin self-exams in their early teen years and should conduct the self-checks regularly throughout their lifetime. Although a role for dermatophytes, yeasts, and molds in the pathogenesis of pure erythrasma has been disproven, topical antifungal formulations .1 Luminecescence with a Wood’s have been used with success to manage the condi- Lamp reveals a coral pink fluorescence that confirms tion and are described as first-line treatment the presence of C. minutissimum and supports the diag- options.9 Topical miconazole,12 clotrimazole,13 and nosis. The diagnosis may be missed if the patient has econazole9 have all been shown effective for ery- bathed in previous 24 hours; bathing may wash away thrasma. In one trial involving 61 patients with coproporphyrin III, the pigment produced by C. fungal infection or erythrasma, subjects were ran- minutissimum that causes fluorescence. Fungal culture domized to use topical tioconazole base 1% w/w or may be used to rule out concomitant fungal infection. econazole nitrate 1% creams for a mean treatment Erythrasma has been found to have a higher preva- period of 40 and 38 days respectively.14 All but two lence in diabetics and the obese.1,2 patients in each arm achieved clinical and mycolog- ic cure and described treatment as generally Treatment Options acceptable, though mild intermittent pruritus was 250mg four times daily for 14 days is reported with econazole. Again, creams may not be described as the systemic antibiotic treatment of ideal for use in skin folds and interdigital spaces. choice for erythrasma.1 Yet systemic antibiotics are A new ketoconazole foam 2% formulation (Extina, described as a third-line treatment option for erythras- Stiefel), has been a welcome new treatment option for ma, and they confer limited efficacy for affected toe- erythrasma. The foam vehicle (VersaFoam HF) is a webs.10,11 As physicians have become increasingly hydroethanolic formulation that is neither hydrating aware of antibiotic resistance and its potential long- nor drying. It is designed to rapidly dissolve at skin term impact on patient care, there have been efforts to temperature leaving little to no residue. As such, it is reduce the use of systemic antibiotics. Furthermore, ideal for application to skin folds. The foam can be systemic medications in general tend to present a easily applied to various body sites large and small greater risk of side effects and/or drug interactions and is readily applied to hair-bearing skin, making it compared to topical agents. Given that erythrasma is a suitable for use in the axilla and hair-bearing chest

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and abdomen. It is also easily and comfortably applied ria may, like dermatophytes, colonize moist footwear.3 to the toe webs. Patients with erythrasma involving the toe webs may Ketoconazole has long been recognized as having a need to disinfect or replace shoes to eliminate expo- broad spectrum of activity.15 It confers documented sure to bacteria. Once clear, patients should be anti-inflammatory and antibacterial effects.16 advised to allow their shoes to thoroughly dry An added benefit of topical ketoconazole for the between wearing, perhaps alternating footwear every- management of erythrasma is that the broad-spectrum other-day, if needed to allow drying. antifungal will address any concomitant fungal compo- Patients with a history of recalcitrant or recurrent nent of the presentation, eliminating the need for cul- erythrasma may be directed to prophylactically apply ture and optimizing the likelihood of complete cuta- topical ketaconozole foam to previously affected areas neous clearance. once daily. ■ —Joseph Bikowski, MD

Prevention 1. Hernandez RG, Cohen BA. Insect Bite-Induced Hypersensitivity and the SCRATCH Principles: A To reduce the likelihood of recurrence of erythras- New Approach to Papular Urticaria. Pediatrics. 2006 118: 1: 189- 196. ma, patients must make efforts to reduce bacterial 2. Holdiness MR. Management of cutaneous erythrasma. Drugs. 2002;62(8):1131-41. 3. Scheinfeld NS. and dermatology. Clin Dermatol. 2004 Jul-Aug;22(4):303-9. colonization and minimize moisture in the skin 4. Conklin RJ. Common cutaneous disorders in athletes. Sports Med. 1990 Feb;9(2):100-19. folds. The use of antibacterial washes has been rec- 5. Gupta S. Pityriasis rotunda mimicking tinea cruris/corporis and erythrasma in an Indian patient. ommended, though no published data are available. J Dermatol. 2001 Jan;28(1):50-3. 6. Aste N, Pau M, Aste N. Pityriasis versicolor on the groin mimicking erythrasma. Mycoses. 2004 Advise patients to thoroughly dry the skin after Jun;47(5-6):249-51. bathing. 7. Karakatsanis G, Vakirlis E, Kastoridou C, Devliotou-Panagiotidou D. Coexistence of pityriasis versicolor and erythrasma. Mycoses. 2004 Aug;47(7):343-5. Although standard laundering practices are expect- 8. Marks R, Ramnarain ND, Bhogal B, Moore NT. The erythrasma microorganism in situ: studies ed to prevent bacterial colonization of clothing, bacte- using the skin surface biopsy technique. J Clin Pathol. 1972 Sep;25(9):799-803. 9. Montes LF, McBride ME, Johnson WP, Owens DW, Knox JM. Ultrastructural study of the host-bac- terium relationship in erythrasma. J Bacteriol. 1965 Nov;90(5):1489-91. 10. Barkham MC, Smith AC. Erythrasma in Treatment of Skin Disease: Comprehensive Therapeutic Allergic Contact Dermatitis Tips Strategies, Lebwohl MG, et al., eds. 2005 Mosby, Incorporated 11. Seville RH, Somerville DA. The treatment of erythrasma in a hospital for the mentally subnor- There are many things patients with proven or suspected contact mal.Br J Dermatol. 1970 May;82(5):502-6 dermatitis should and should not do. Among various tips for 12. Pitcher DG, Noble WC, Seville RH. Treatment of erythrasma with miconazole. Clin Exp Dermatol. pediatric patients (PracticalDermatology.com), Pamela 1979 Dec;4(4):453-6. 13. Clayton YM, Knight AG. A clinical double-blind trial of topical miconazole and clotrimazole Chayavichitsilp, MD and Sharon E. Jacob, MD offer these tips. against superficial fungal infections and erythrasma. Clin Exp Dermatol. 1976 Sep;1(3):225-32. 14. Grigoriu D, Grigoriu A. Double-blind comparison of the efficacy, toleration and safety of tio- Do wear socks with shoes. It is important to remember that conazole base 1% and econazole nitrate 1% creams in the treatment of patients with fungal infec- shoes—including many sandles and summer footwear—may con- tions of the skin or erythrasma. Dermatologica. 1983;166 Suppl 1:8-13. 15. Van Tyle JH. Ketoconazole. Mechanism of action, spectrum of activity, pharmacokinetics, drug tain ingredients such as thiuram and p-tert-butyl formaldehyde interactions, adverse reactions and therapeutic use. Pharmacotherapy. 1984 Nov-Dec;4(6):343- resin.17,18,19 These are common allergens known to cause contact 73. 16. Van Cutsem J, Van Gerven F, Cauwenbergh G, Odds F, Janssen PA. The antiinflammatory effects dermatitis of the feet. Wearing socks creates a barrier between of ketoconazole. A comparative study with hydrocortisone acetate in a model using living and the foot and the shoe and is an important measure in preventing killed Staphylococcus aureus on the skin of guinea-pigs. J Am Acad Dermatol. 1991 Aug;25(2 Pt 1):257-61. 19 contact sensitization to shoe material allergens. 17. Teixeira, M., et al., Severe contact allergy to footwear in a young child. Contact Dermatitis, 2005. 52(3): p. 159-60. Don’t allow henna tattoos. Henna tattoos are becoming more 18. Warshaw, E.M., et al., Shoe allergens: retrospective analysis of cross-sectional data from the popular among adolescents. These tattoos can be ‘laced’ with north american contact dermatitis group, 2001-2004. Dermatitis, 2007. 18(4): p. 191-202. para-phenylenediamine (PPD), a hair dye which is prohibited by 19. Castanedo-Tardan MP, Gelpi C, Jacob SE. Allergic contact dermatitis to Crocs. Contact Dermatitis. 2008 Apr;58(4):248-9. the FDA for application to the skin. This chemical is a significant 20. Jacob, S. and T. Zapolanski, Allergen Focus: Focus on T.R.U.E. Test Allergen #20: contact sensitizer20,21 and has been associated with serious reac- Paraphenylenediamine. Skin & Aging, 2005. 13(6): p. 31 - 34 22,23 21. Blair, J., R. Brodell, and S. Nedorost, Dermatitis associated with henna tattoo: "Safe" alterna- tions in children. PPD can also cross-react with similar com- tive to permanent tattoos carries risk. Postgraduate Medicine, 2004 116(3). pounds commonly found in sunscreen with PABA, and certain 22. Jung, P., et al., The extent of black henna tattoo's complications are not restricted to PPD-sen- heart and diabetic medications such as sulfonamides and sul- sitization. Contact Dermatitis, 2006. 55(1): p. 57. 20 23. Sosted, H., et al., Severe allergic hair dye reactions in 8 children. Contact Dermatitis, 2006. fonylureas. Therefore, it is best to avoid. 54(2): p. 87-91.

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