Interaction of mucosal immune system and infections in infancy: implications in allergy.

The immune responses to viral antigens and other environmental agents to which the mucosal surfaces of the neonate are exposed during the perinatal period and early infancy are intimately related to the mechanism of innate immunologic reactivity of the mother-and, possibly, to the immunologic elements in the products of lactation for a breast-feeding infant-and the nutritional homeostasis of the neonate. The role of these factors in protecting against pathogenicity of viral infections in the respiratory and intestinal tract, and their impact on the development of allergic disease state in childhood will be reviewed.