Cutaneous delayed-type hypersensitivity in patients with atopic dermatitis: reactivity to surfactants.

BACKGROUND: Patients with atopic dermatitis (AD) have abnormalities in skin barrier function, and are predisposed to developing cutaneous delayed-type hypersensitivity. Soap and detergents are known to exacerbate the breakdown of the skin barrier. OBJECTIVE: We sought to assess whether atopic patients in our database were more likely than nonatopic patients to patch test positive to the surfactants cocamidopropyl betaine (CAPB) and cocamide diethanolamide (DEA), or to the surfactant precursor amidoamine. METHODS: Between January 1, 2001, and the present, a total of 1674 patients underwent patch testing to the North American Contact Dermatitis Group standard screening series. The incidence of positive patch test results to CAPB, cocamide DEA, and amidoamine among patients with AD (n = 242) and without AD (n = 1422) was assessed. Statistical analysis was done using a χ(2) test. RESULTS: AD was associated with contact hypersensitivity to CAPB, but not to cocamide DEA or amidoamine. LIMITATIONS: This was a retrospective study of patients evaluated for suspected allergic contact dermatitis and, therefore, matching for gender, age, or other parameters was not possible. Our population was geographically limited to metropolitan Kansas City, MO, and metropolitan New York City, NY. CONCLUSIONS: Patients with AD should avoid the use of skincare products containing the surfactant CAPB.