Cutaneous delayed-type hypersensitivity in patients with atopic dermatitis

Background: Literature on the relationship between atopic dermatitis (AD) and cutaneous delayed-type hypersensitivity is inconclusive. Objective: We sought to compare the rates of positive patch test reactions to allergens on the North American Contact Dermatitis Group (NACDG) standard tray among patients with and without AD, and, to assess whether atopic patients in our database were more likely to patch test positive to certain classes of allergens. Methods: A total of 2305 patients underwent patch testing to the NACDG standard screening series. The incidence of positive patch test reactions among patients with AD (n = 297) and without AD (n = 2008) was assessed. Statistical analysis was done using a chi(2) test with Yates continuity correction. Results: Compared with nonatopic patients, those with AD were statistically more likely to have positive patch tests. AD was associated with contact hypersensitivity to nickel, cobalt, and chromium, but was not associated with contact sensitization to fragrances. Limitations: Only patients suspected of having allergic contact dermatitis were tested. Our population was geographically limited to metropolitan Kansas City (including Kansas City, MO, Kansas City, KS, and the adjoining suburbs). Conclusion: Compared with nonatopics, patients with AD are significantly more likely to have at least 1 positive patch test reaction and to develop contact hypersensitivity to metal allergens.