Role of foods in irregular aggravation of atopic dermatitis.

Although it is well known that patients with atopic dermatitis often show unpredictable, irregular aggravation of skin lesions, there are no previously published studies examining trigger factors for such unpredictable aggravation. We investigated whether foods play a role in the unpredictable, irregular worsening of atopic dermatitis. The patient group included 195 Japanese adult patients with atopic dermatitis who showed unpredictable, irregular aggravation of skin lesions. They were hospitalized and openly challenged with suspected foods. Photographs of representative skin lesion sites were taken at baseline and before and after the challenge. Challenge-positive foods were determined by evaluating the comparable before-after challenge photographs. One to three (average: 1.7) challenge-positive foods were confirmed in 86 (44%) of the 195 patient examined. Predominant offending foods were chocolate, cheese, coffee, yogurt and some Japanese foods such as glutinous rice cake, soy sauce and fermented soybeans. Specific IgE values to the offending foods were mostly negative. Patients were asked to exclude challenge-positive foods from their diets. They were then discharged and followed up for 3 months at our outpatient clinic. Exclusion of the offending foods for 3 months brought about a progressive improvement of the disease. These results suggest that foods play an important role in unpredictable, irregular aggravation of skin lesions in patients with atopic dermatitis.