Frequency of atopic dermatitis and relevance of food allergy in adults in Germany

Many factors may aggravate atopic dermatitis. The aim of this study was to determine the frequency of atopic dermatitis in an unselected population sample and to evaluate the role of food allergy. Patients with atopic dermatitis were recruited from the population in Berlin, Germany, using a postal questionnaire. Skin prick tests for allergens were performed, followed by food challenges. A total of 1739 questionnaires was returned. In all, 23.5% of patients stated that they had atopic dermatitis, and 146 persons (8.4%) fulfilled our atopic dermatitis criteria after a detailed telephone interview. Of these, 111 were examined, and 28 (1.6%) were identified as currently suffering from atopic dermatitis. Twenty-seven patients were further evaluated: 9/27 were found to be skin prick test negative, 19/27 were skin prick test positive either to pollen and/or food allergens. Nine of 27 were challenged with the suspected food allergen: 1/9 showed a worsening of the eczema, 3/9 had oral symptoms, and 5/9 were negative. In conclusion, only 20% of adults with a positive history of atopic dermatitis show active eczema lesions at a given time point. The data indicate that most individuals with atopic dermatitis were sensitized against pollen allergens and according to that, pollen-associated food allergens. A non-selected AD patient cohort does not frequently suffer from clinically relevant pollen-associated food allergy.