Food allergy and complementary feeding.

The relationship between complementary feeding and the development of atopic disease is the source of significant interest and debate in both the scientific and lay communities. A small number of early studies, which had considerable influence on recommended feeding practices, reported protective effects associated with delaying the introduction of commonly allergenic foods such as cow's milk, egg, and nuts. Despite more conservative recommendations, however, food allergy prevalence has continued to rise. Our understanding of the development of food allergy, its relationship with IgE sensitization and atopic dermatitis, and the relationship of each of these outcomes with the timing of food introduction has evolved considerably. Based on multiple observational studies, and extrapolating from immunotherapy trials and animal models of mucosal immunity, there is mounting evidence that delayed introduction or avoidance of commonly allergenic foods is at best neutral and may be detrimental with regard to atopic outcomes. There is an obvious and critical need for additional high-caliber studies to further evaluate this connection. In the meantime, multiple health considerations, not allergy alone, should be involved in decisions regarding nutritional intake, including common allergenic foods, during the period of transition to the family diet.