Can early introduction of egg prevent egg allergy in infants? A population-based study

BackgroundInfant feeding guidelines have long recommended delaying introduction of solids and allergenic foods to prevent allergy in high-risk infants, despite a paucity of evidence.ObjectiveWe aimed to determine whether confirmed egg allergy in 12-month-old infants is associated with (1) duration of breast-feeding and (2) ages of introducing egg and solids.MethodsIn a population-based cross-sectional study (HealthNuts) parents reported on infant feeding and potential confounding factors before skin prick testing for egg white. Egg-sensitized infants were then offered an egg oral food challenge. Multiple logistic regression was used to investigate associations between diet and egg allergy adjusted for possible confounding factors.ResultsA total of 2589 infants (73% response) participated. Compared with introduction at 4 to 6 months, introducing egg into the diet later was associated with higher risks of egg allergy (adjusted odds ratios [ORs], 1.6 [95% CI, 1.0-2.6] and 3.4 [95% CI, 1.8-6.5] for introduction at 10-12 and after 12 months, respectively). These findings persisted even in children without risk factors (OR, 3.3 [95% CI, 1.1-9.9]; 10-12 months). At age 4 to 6 months, first exposure as cooked egg reduced the risk of egg allergy compared with first exposure as egg in baked goods (OR, 0.2 [95% CI, 0.06-0.71]). Duration of breast-feeding and age at introduction of solids were not associated with egg allergy.ConclusionsIntroduction of cooked egg at 4 to 6 months of age might protect against egg allergy. Changes in infant feeding guidelines could have a significant effect on childhood egg allergy and possibly food allergy more generally.