Influence of early-life exposures on food sensitization and food allergy in an inner-city birth cohort

Abstract

Rationale Previous data suggest that food allergy may be more common in inner-city children; however, these studies have not collected data on both sensitization and clinical reactivity, or early life exposures. Methods Children in the URECA birth cohort were followed through age 5 years. Household exposures, diet, clinical history, and physical examinations were assessed yearly; specific-IgE to milk, egg, and peanut were measured at 1, 2, 3, and 5 years. Based on sensitization (IgE≥0.35 kU/L) and clinical history over the five-year period, children were classified as food allergic (FA), possibly allergic, sensitized but tolerant, or not allergic/not sensitized. Results 516 children were included. Overall, 55.4% were sensitized (milk 46.7%, egg 31.0%, peanut 20.9%), while 9.9% were categorized as FA (peanut 6.0%, egg 4.3%, milk 2.7%, 2.5% >1 food). The remaining children were categorized as possibly allergic (17.0%), sensitized but tolerant (28.5%), and not sensitized (44.6%). Eighteen (3.5%) reported reactions to foods for which IgE was not measured. Food-specific IgE levels were similar in FA versus sensitized but tolerant children, except for egg, which was higher in FA at ages 1 and 2. FA was associated with recurrent wheeze, eczema, aeroallergen sensitization, male gender, breastfeeding, and lower endotoxin exposure in year 1, but not with race/ethnicity, income, tobacco exposure, maternal stress, or early introduction of solid foods. Conclusions Even given that this was designed to be a high-risk cohort, the cumulative incidence of food allergy is extremely high, especially considering the strict definition of food allergy that was applied and that only 3 common allergens were included.

Prevalence estimates and risk factors for early childhood wheeze across Europe: the EuroPrevall birth cohort

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