CONTACT DERMATITIS Differentiation of Latex Allergy From Irritant Contact Dermatitis Craig Burkhart, MD, MPH; Julie Schloemer MD; Matthew Zirwas, MD PRACTICE POINTS • The term latex allergy often is used as a general diagnosis to describe 3 types of reactions to natural rubber latex, including irritant contact dermatitis, allergic contact dermatitis (type IV hypersensitivity reaction), and true latex allergy (type I hypersensitivity reaction). • The latex skin prick test is considered the gold standard for diagnosis of true latex allergy, but this method is not available in the United States. In vitro assay for latex-specific immunoglobulin E antibodies is the best alternative. copy The term latex allergy refers to a hypersensitiv- atex allergy is an all-encompassing term used to ity to products containing natural rubber latex. describe hypersensitivity reactions to products Individuals with true latex allergy have developed Lcontaining natural rubber latex from the Hevea type I (immediate) hypersensitivity due to previous brasiliensisnot tree and affects approximately 1% to 2% sensitization and production of immunoglobulin E of the general population.1 Although latex gloves antibodies. Other forms of adverse reactions to are the most widely known culprits, several other latex-containing products may develop, including commonly used products can contain natural rubber irritant contact dermatitis and type IV (delayed)Do latex, including adhesive tape, balloons, condoms, hypersensitivity reactions, although they do not rubber bands, paint, tourniquets, electrode pads, and indicate true latex allergy. Several diagnostic Foley catheters.2 The term latex allergy often is used tests are available to differentiate true latex as a general diagnosis, but there are in fact 3 distinct allergy from irritant contact dermatitis and allergic mechanisms by which individuals may develop an contact dermatitis. It is crucial to determine the adverse reaction to latex-containing products: irri- type of hypersensitivity in patients labeled with tant contact dermatitis, allergic contact dermatitis “latex allergy” in order to establish the most effec- (type IV hypersensitivity) and true latex allergy tive treatment regimen. CUTIS (type I hypersensitivity). Cutis. 2015;96:369-371, 401. Irritant Contact Dermatitis Irritant contact dermatitis, a nonimmunologic reac- tion, occurs due to mechanical factors (eg, friction) or contact with chemicals, which can have irritating and dehydrating effects. Individuals with irritant contact dermatitis do not have true latex allergy and will not necessarily develop a reaction to products containing natural rubber latex. Incorrectly attrib- Dr. Burkhart is from the Heritage College of Medicine, University uting these irritant contact dermatitis reactions to of Toledo, Ohio, and the College of Osteopathic Medicine and latex allergy and simply advising patients to avoid Life Sciences, Ohio University, Athens. Dr. Schloemer is from the all latex products (eg, use nitrile gloves rather Department of Dermatology, Wright State University, Dayton. than latex gloves) will not address the underlying Dr. Zirwas is from the Department of Dermatology, The Ohio State problem. Rather, these patients must be informed University, Columbus. The authors report no conflict of interest. that the dermatitis is a result of a disruption to Correspondence: Craig Burkhart, MD, MPH, 5600 Monroe St, the natural, protective skin barrier and not an aller- Ste 106B, Sylvania, OH 43560 ([email protected]). gic reaction. WWW.CUTIS.COM VOLUME 96, DECEMBER 2015 369 Copyright Cutis 2015. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. Contact Dermatitis Allergic Contact Dermatitis found to be sensitized to latex, only 2.4% had clinically Allergic contact dermatitis to rubber is caused by a symptomatic allergic reactions. type IV (delayed) hypersensitivity reaction and is the result of exposure to the accelerators present in Testing for Latex Allergy rubber products in sensitive individuals. Individuals Several diagnostic tests are available to establish a experiencing this type of reaction typically develop diagnosis of type I sensitization or true latex allergy. localized erythema, pruritus, and urticarial lesions Skin prick testing is an in vivo assay and is the gold 48 hours after exposure.3 Incorrectly labeling this standard for diagnosing IgE-mediated type I hypersen- problem as latex allergy and recommending non- sitivity to latex. The test involves pricking the skin latex rubber substitutes (eg, hypoallergenic gloves) of the forearm and applying a commercial extract of likely will not be effective, as these nonlatex replace- nonammoniated latex to monitor for development of ment products contain the same accelerators as do a wheal within several minutes. The skin prick test latex gloves. should be performed in a health care setting equipped with oxygen, epinephrine, and latex-free resuscitation True Latex Allergy equipment in case of anaphylaxis following exposure. The most severe form of latex allergy, often referred Although latex skin prick testing is the gold standard, to as true latex allergy, is caused by a type I (immedi- it is rarely performed in the United States because ate) hypersensitivity reaction mediated by immuno- there is no US Food and Drug Administration– globulin E (IgE) antibodies. Individuals experiencing approved natural rubber latex reagent.3 Consequently, this type of reaction have a systemic response to latex physicians who wish to perform skin prick testing for proteins that may result in fulminant anaphylaxis. latex allergy are forced to develop improvised reagents Individuals with true latex allergy must absolutely from the H brasiliensiscopy tree itself or from highly aller- avoid latex products, and substituting nonlatex prod- genic latex gloves. Standardized latex allergens are ucts is the most effective approach. commercially available in Europe. The most noninvasive method of latex allergy test- Latex Reactions in Medical Practice ingnot is an in vitro assay for latex-specific IgE antibodies, The varying propensity of certain populations to which can be detected by either a radioallergosorbent develop latex allergy has been well documented; for test (RAST) or enzyme-linked immunosorbent assay example, the prevalence of hypersensitivity in patients (ELISA). The presence of antilatex IgE antibodies with spina bifida ranges from 20% to 65%, figuresDo that confirms sensitization but does not necessarily mean are much higher than those reported in the general the patient will develop a symptomatic reaction fol- population.3 This hypersensitivity in patients with lowing exposure. Due to the unavailability of a stan- spina bifida most likely results from repeated exposure dardized reagent for the skin prick test in the United to latex products during corrective surgeries and diag- States, evaluation of latex-specific serum IgE levels nostic procedures early in life. Atopic individuals, such may be the best alternative. While the skin prick test as those with allergic rhinitis, eczema, and asthma, has the highest sensitivity, the sensitivity and speci- have a 4-fold increased risk for developing latex allergy ficity of latex-specific serum IgE testing are 50% to compared to nonatopic individuals.CUTIS4 The risk of latex 90% and 80% to 87%, respectively.6 allergy among health care workers is increased due The wear test (also known as the use or glove to increased exposure to rubber products. One study provocation test), can be used to diagnose clini- found that the risk of latex sensitization among health cally symptomatic latex allergy when there is a dis- care workers exposed to products containing latex was crepancy between the patient’s clinical history and 4.3%, while the risk in the general population was only results from skin prick or serum IgE antibody testing. 1.37%.1 Those at highest risk for sensitization include To perform the wear test, place a natural rubber latex dental assistants, operating room personnel, hospital glove on one of the patient’s fingers for 15 minutes housekeeping staff, and paramedics or emergency med- and monitor the area for development of urticaria. ical technicians.3 However, sensitization documented If there is no evidence of allergic reaction within on laboratory assessment does not reliably correlate 15 minutes, place the glove on the whole hand for an with symptomatic allergy, as many patients with a additional 15 minutes. The patient is said to be non- positive IgE test do not show clinical symptoms. reactive if a latex glove can be placed on the entire Schmid et al4 demonstrated that a 1.3% prevalence hand for 15 minutes without evidence of reaction.3 of clinically symptomatic latex allergy among health Lastly, patch testing can differentiate between care workers may approximate the prevalence of irritant contact and allergic contact (type IV hyper- latex allergy in the general population. In a study by sensitivity) dermatitis. Apply a small amount of Brown et al,5 although 12.5% of anesthesiologists were each substance of interest onto a separate disc and 370 CUTIS® WWW.CUTIS.COM Copyright Cutis 2015. No part of this publication may be reproduced, stored, or transmitted without the prior written permission of the Publisher. Contact Dermatitis Presence or history of symptoms suggesting allergic reaction to latex-containing products History of life-threatening reaction after exposure to natural