Children with both atopic dermatitis and allergic sensitization at age 1 year have a more than 7-fold increased risk for developing asthma as well as an increased risk for developing food allergies by age 3 years, according to a recent study.The study included 2311 children who underwent skin prick testing at age 1 year and were assessed for atopic dermatitis. Children who produced a 2 mm or larger wheal than that elicited by controls in response to 10 inhalant or food allergens were considered sensitized. At age 3, they were evaluated for asthma, allergic rhinitis, food allergy, and atopic dermatitis.
After adjusting for common confounders, the researchers found that atopic dermatitis without allergic sensitization was not associated with an increased risk of asthma at age 3 years (relative risk [RR] 0.46). However, atopic dermatitis with allergic sensitization was associated with a more than 7-fold increased risk of asthma (RR 7.04). Atopic dermatitis and allergic sensitization had significant interactions on the additive (relative excess risk 5.06) and multiplicative (ratio of RRs 5.80) scales in association with asthma risk. Additionally, there was a positive additive interaction between atopic dermatitis and allergic sensitization in their effects on the risk for developing food allergies (relative excess risk 15.11).
“Atopic dermatitis without concomitant allergic sensitization was not associated with an increased risk of asthma,” the researchers concluded. “In combination, atopic dermatitis and allergic sensitization had strong interactive effects on both asthma and food allergy risk at age 3 years.”
—Melissa Weiss
Reference:
Tran MM, Lefebvre DL, Dharma C, et al. Predicting the atopic march: Results from the Canadian Healthy Infant Longitudinal Development Study [published online November 15, 2017]. J Allergy Clin Immunol. https://dx.doi.org/10.1016/j.jaci.2017.08.024.
