Epidemiological, Clinical, and Allergy Profile of Patients With Atopic Dermatitis and Hand Eczema: Evaluation of the Spanish Contact Dermatitis Registry (REIDAC).

Background: Hand eczema is common in patients with atopic dermatitis (AD), but few studies have described the characteristics of these patients in large, representative populations from different geographic regions and occupational settings.
Objective: To describe the epidemiological, clinical, and allergy profile of patients with hand eczema who underwent patch testing and compare patients with and without AD.
Methods: Analysis of data from the Spanish Contact Dermatitis Registry, a multicenter registry of patients who undergo patch testing in Spain.
Results: We included 1466 patients with hand eczema who were patch tested between January 2018 and June 2020. Those with AD were younger and had had symptoms for longer before testing. They were also more likely to have been exposed to occupational triggers (38% vs 53% for patients without AD). The only profession for which significant differences were found was hairdressing. The most common allergens were nickel sulfate, methylchloroisothiazolinone/methylisothiazolinone, cobalt chloride, potassium dichromate, fragrance mixes I and II, and formaldehyde. The most common diagnoses were allergic contact dermatitis (24% vs 31% in patients with and without AD, P=.0224) and irritant contact dermatitis (18% and 35% respectively, P<.001).
Conclusions: AD is common in patients with predominant hand eczema who undergo patch testing. Patients with hand eczema and AD have different clinical and epidemiological characteristics to hand eczema patients in general and their final diagnosis following patch testing is also different.
(Copyright © 2021 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.)