Food Allergy Is an Important Risk Factor for Childhood Asthma, Irrespective of Whether It Resolves

BACKGROUND: The risk of developing asthma in those with early food allergy is unknown, particularly when early life food allergy has resolved. OBJECTIVE: To understand whether challenge-proven food allergy in infancy increases the risk of asthma at age 4 years, using data from a population-based cohort. METHODS: A total of 5,276 12-month-old infants were recruited using a population-based sampling frame. Infants underwent skin prick test to egg, peanut, and sesame and those with a detectable skin prick test result had oral food challenges. At age 4 years, food challenges were repeated to determine persistence or resolution of food allergy. The association between food allergy and doctor-diagnosed asthma was examined using binomial regression in 2,789 participants. RESULTS: Children with food allergy at age 1 year had an increased risk of asthma (1 food allergy: relative risk [RR], 1.69; 95% CI, 1.29-2.21; 2 or more food allergies: RR, 2.76; 95% CI, 1.94-3.92). The risk of asthma was highest in children with food allergy and coexistent eczema in infancy (RR, 2.87; 95% CI, 2.22-3.70). Transient food allergy and persistent food allergy were both associated with an increased risk of asthma (transient egg allergy: RR, 1.92; 95% CI, 1.46-2.51; persistent egg allergy: RR, 2.60; 95% CI, 1.76-3.85). CONCLUSIONS: Asthma at age 4 years is twice as common in those with challenge-proven food allergy at age 1 year, irrespective of whether the food allergy subsequently resolves. Children with 2 or more food allergies and those with coexistent eczema were almost 3 times as likely to develop asthma compared with those with no food allergies. (C) 2017 American Academy of Allergy, Asthma & Immunology