Atopic dermatitis at preschool age and contact allergy in adolescence: a population-based cohort study

Background Atopic dermatitis (AD) is characterized by an impaired skin barrier, which can allow enhanced penetration of allergens. It is not clear whether AD influences the risk of developing contact allergy. Objectives To examine the association between AD at preschool age and contact allergy at 16 years of age. Methods At 16 years of age, 2215 adolescents from the population-based cohort BAMSE were included. These adolescents had been followed with repeated questionnaires regarding AD throughout childhood, and contact allergy was assessed by skin patch test at 16 years. Results AD at preschool age was associated with contact allergy to at least one of the tested substances at 16 years of age among boys [adjusted odds ratio (OR) 1 center dot 51, 95% confidence interval (CI) 1 center dot 03-2 center dot 20] but not among girls (adjusted OR 0 center dot 77, 95% CI 0 center dot 54-1 center dot 10). AD at preschool age was not associated with contact allergy to nickel in either boys or girls. In contrast, AD at preschool age was associated with contact allergy to fragrance mix I (adjusted OR 3 center dot 10, 95% CI 1 center dot 66-5 center dot 80). This association was observed especially for AD at preschool age in combination with IgE sensitization to airborne or food allergens (adjusted OR 3 center dot 80, 95% CI 1 center dot 67-8 center dot 61). Conclusions The results suggest that AD in early childhood may be associated with contact allergy to fragrances, but not to nickel, in adolescence.