Contact Sensitivity in Patients with Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic and relapsing, non-contagious inflammatory skin disorder, characterized by skin barrier impairment and baseline immune irregularities. The literature on the relationship between AD and cutaneous delayed-type hypersensitivity is inconclusive. There is an ongoing debate whether contact sensibility (CS) is found more or less often among patients with AD. Aim of the study was to evaluate the incidence of contact sensitivity (positive patch test reactions) in patients with and without AD. We patch tested a total of 2143 patients (563 men and 1580 women). There were 226 patients with history of AD; 61 (27%) men and 165 (73%) women. The patient group without AD consisted of 1917 patients, 502 (26%) male and 1415 (74%) female patients, who were referred to our Department with clinical suspicion of allergic contact dermatitis (ACD). A patch test was performed with the baseline series, and readings were performed on days D2, D3, and D7. Among patients with AD, 109 (48.2%) had a positive patch test reaction to at least one allergen, whereas 1094 (57.1%) patients with no history of AD had a positive patch test reaction. The most common positive allergens in patients with AD were nickel (II) sulfate (13.3%), thimerosal (12.4%), cobalt (II) chloride (11.5%), methylisothiazolinone (MI) (8.4%), fragrance mix I (6.6%), potassium dichromate (5.3%), methyldibromo glutaronitrile (4.0%), and carba mix (4.0%). The results of our study agree with previous findings that there is no significant difference in prevalence of CS between the atopic and nonatopic populations.