Incidence and Early‐Life Risk Factors for Food Allergy in a Spanish Birth Cohort

AIM: The prevalence of food allergy has increased in recent decades. We aimed to determine the cumulative incidence of food allergy in early childhood and to identify associated risk factors. METHODS: We conducted a prospective birth cohort study including 1006 newborns recruited over one year at a single hospital in Spain and followed until 4 years of age. Data were collected at birth and through structured telephone interviews during follow-up. Children with suspected food allergy underwent skin prick testing, specific serum IgE measurement and open oral food challenges when indicated. RESULTS: The cumulative incidence of food allergy was 7.2% (72/1006). Independent risk factors for IgE-mediated food allergy included hospitalization for bronchospasm (adjusted odds ratio [aOR] 2.37; 95% CI 1.07-5.26), atopic dermatitis (aOR 7.52; 95% CI 3.77-15.01), maternal asthma (aOR 3.12; 95% CI 1.30-7.53) and paternal allergic rhinitis (aOR 2.79; 95% CI 1.31-5.94). Proton-pump inhibitor use, absence of daycare attendance and early-onset atopic dermatitis were associated with non-IgE-mediated food allergy. CONCLUSION: In this Spanish birth cohort, food allergy affected 7.2% of children by age 4. Atopic dermatitis was the main risk factor for IgE-mediated food allergy, while potentially modifiable early-life exposures were associated with non-IgE-mediated forms.