Backgorund: Food allergy is a rare disorder among breastfeeding babies.
Objective: Our aim was to identify responsible allergens in human milk.
Methods: We studied babies developing allergic symptoms at the time they were breastfeeding. Skin prick tests (SPT) were performed with breast milk and food allergens. Specific IgE was assessed and IgE Immunoblotting experiments with breast milk were carried out to identify food allergens. Clinical evolution was evaluated after a maternal free diet.
Results: Five babies had confirmed breast milk allergy. Peanut, white egg and/or cow's milk were demonstrated as the hidden responsible allergens. No baby returned to develop symptoms once mother started a free diet. Three of these babies showed tolerance to other food allergens identified in human milk.
Conclusion: A maternal free diet should be recommended only if food allergy is confirmed in breastfed babies.
Keywords: breastfed infants; food allergy; hidden allergens; human milk.