Ontogeny of the allergic inflammatory response.

The ability to produce allergic responses begins early in fetal life along with the development of other elements of the immune system. Among the most interesting questions related to the development of allergic disease are whether the fetus in utero commonly is exposed to sufficient allergen to induce IgE production and how much the mother's immune responses affect the developing fetal immune system. After birth, it seems that many factors, including the frequency and severity of infections and the timing and intensity of allergen and animal exposures, continue to influence immune development.