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

The risk of developing asthma in those with early food allergy is unknown, particularly when early life food allergy has resolved.

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.

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.

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).

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.