Prevalence of atopic dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis

BACKGROUND: Atopic diseases are common in children and adolescents. However, epidemiological knowledge is sparse for hand eczema and allergic contact dermatitis in this age group. Furthermore, no population-based studies have evaluated the prevalence of atopic diseases and hand and contact dermatitis in the same group of adolescents. OBJECTIVES: To assess prevalence measures of atopic dermatitis (AD), asthma, allergic rhinitis and hand and contact dermatitis in adolescents in Odense municipality, Denmark. METHODS: The study was carried out as a cross-sectional study among 1501 eighth grade school children (age 12-16 years) and included questionnaire, interview, clinical examination and patch testing. RESULTS: The lifetime prevalence of AD was 21.3% (girls 25.7% vs. boys 17.0%, P < 0.001) using predefined questionnaire criteria. The 1-year period prevalence of AD was 6.7% and the point prevalence 3.6% (Hanifin and Rajka criteria). In the interview the lifetime prevalence of inhalant allergy was estimated as 17.7% (6.9% allergic asthma, 15.7% allergic rhinitis). The lifetime prevalence of hand eczema based on the questionnaire was 9.2%, the 1-year period prevalence was 7.3% and the point prevalence 3.2%, with a significant predominance in girls. A significant association was found both between AD and inhalant allergy, and between AD and hand eczema using lifetime prevalence measures. The point prevalence of contact allergy was 15.2% (girls 19.4% vs. boys 10.3%, P < 0.001), and present or past allergic contact dermatitis was found in 7.2% (girls 11.3% vs. boys 2.5%). Contact allergy was most common to nickel (8.6%) and fragrance mix (1.8%). CONCLUSIONS: High prevalence figures were found for atopic diseases, hand eczema and allergic contact dermatitis, and the diseases were closely associated. A considerable number of adolescents still suffers from AD, and a considerable sex difference was noted for hand eczema and allergic contact dermatitis. Nickel allergy and perfume allergy were the major contact allergies. In the future this cohort of eighth grade school children will be followed up with regard to the course and development of atopic diseases, hand eczema and contact dermatitis.