Concomitant Allergic Dermatitis, Polysensitization Common in Tough-to-Treat Atopic Dermatitis

In a population of children and adults with difficult-to-treat atopic dermatitis (AD), high rates of concomitant allergic contact dermatitis (ACD) and polysensitization are reported, according to the results of a retrospective analysis published in the Journal of the European Academy of Dermatology and Venereology.¹

The investigators sought to examine the occurrence of ACD in patients with difficult-to-treat AD. They collected clinical and patch test information retrospectively from 48 children and adults with difficult-to-treat AD who were diagnosed with AD based on UK Working Party Criteria² and whose condition was unresponsive to conventional outpatient treatment. The researchers studied the prevalence and relevance of common allergens, evaluated the occurrence of polysensitization, and performed dynamic patch test analysis.

Among the 48 study participants who were diagnosed with AD, the median age was 14.6 years (range, 10.1-19.0 years). Overall, 71% (34 of 48) of the patients were children and 29% (14 of 48) of the participants were adults; 44% (21 of 48) of the patients were men. The mean Eczema and Severity Index score, which was available in 26 of the 48 participants, was 25 (range, 12 to 41).

Overall, 75% (36 of 48) of patients had a concomitant contact allergy, and polysensitization was present in 39% (14 of 36) of these individuals. The prevalence of ACD and polysensitization was equivalent among children and adults. The most common and relevant reactions were observed against wool alcohols, the surfactants cocamidopropyl betaine and dimethylaminopropylamine, bichromate, and fragrance mix I. Based on dynamic pattern analysis, these reactions were mostly of an allergic, not an irritative, nature. 

The investigators concluded that those with difficult-to-treat AD often experience concomitant multiple contact allergies, which may be why AD becomes a difficult-to-treat disease in these patients. Increased awareness of this phenomenon is important because pragmatic implementation of allergen avoidance strategies may help with disease control in this population.

References

1. Boonstra M, Rustemeyer T, Middelkamp-Hup MA. Both children and adult patients with difficult-to-treat atopic dermatitis have high prevalences of concomitant allergic contact dermatitis and are frequently polysensitized [published online March 26, 2018]. J Eur Acad Dermatol Venereol. doi: 10.1111/jdv.14973
2. Williams HC, Burney PG, Pembroke AC, Hay RJ. The U.K. Working Party’s Diagnostic Criteria for Atopic Dermatitis. III. Independent hospital validation. Br J Dermatol. 1994;131(3):406-416.