Prolonged breastfeeding and delayed introduction of whole cow's milk into the diet are factors associated with egg...

Both breastfeeding and the moment at which introduction to solid food occurs have been associated with food allergy.

To evaluate whether prolonged breastfeeding and the delayed introduction of whole cow's milk into an infant's diet are factors that can be associated with egg sensitization.

This was a hospital-based case-control study, matched by age and sex: each study group comprised 97 atopic children. Additionally, logistic regression was used to identify the factors associated with egg protein sensitization.

The most common type of allergic disease among both groups was allergic rhinitis. After adjusting for possible confounding variables, a delayed introduction to whole cow's milk decreased the odds of egg protein sensitization; OR=0.16 (95% CI: 0.07-0.36, p<0.0001). Notably, breastfeeding during the first six months of life, regardless of whether it was the only milk an infant drank, increased the risk for sensitization to chicken eggs; OR=5.54 (95% CI: 2.41-12.7, p<0.0001).

Prolonged breastfeeding, regardless of whether it was the only milk an infant drank, greatly increased the risk of egg sensitization. Interestingly, a delayed introduction to whole cow's milk was associated with a reduced possibility of becoming sensitized to eggs. Further studies are required to elucidate these findings.