Published online: November 15, 2017
The atopic march describes the progression from atopic dermatitis (eczema) during infancy to asthma and allergic rhinitis (hay fever) in later childhood. The connection between atopic dermatitis and asthma has been hypothesized to be a variant of the gene encoding filaggrin, an important skin protein. However, since genetic testing for filaggrin is not typically available in clinical practice, alternative prognostic approaches for children with atopic dermatitis are needed.
In this article recently published in The Journal of Allergy & Clinical Immunology (JACI), Tran and colleagues investigated whether early allergic sensitization enhances the atopic march. Data were used from 2,311 children enrolled in the Canadian Healthy Infant Longitudinal Development (CHILD) Study, a longitudinal, multicenter birth cohort headquartered at McMaster University, Ontario, and funded primarily by the AllerGen Network of Centres of Excellence and the Canadian Institutes of Health Research. At age 1, children were assessed for atopic dermatitis, and underwent skin prick testing to assess for allergic sensitization to six inhalant and four food allergens. At age 3, children underwent a clinical assessment for the presence of asthma, allergic rhinitis, food allergy, and atopic dermatitis.
The authors found that having atopic dermatitis, without allergic sensitization, did not significantly increase children’s risk of developing asthma at age 3. On the other hand, children with atopic dermatitis who were also sensitized to an allergen at age 1 (most to food allergens) were seven times more likely to develop asthma, compared to children without atopic dermatitis or sensitization. These children were also more likely to develop a food allergy. Atopic dermatitis and allergic sensitization had interactive effects on the risk of asthma and food allergy, such that their combined effect exceeded the sum of their individual effects.
The findings suggest that allergic sensitization is important for the progression of the atopic march from atopic dermatitis to other allergy-associated diseases. The combination of atopic dermatitis with allergic sensitization at age 1 can be used to predict at-risk children who are more likely to develop later asthma and food allergy.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.