Ontogeny of the allergic inflammatory response

The ability of the human immune system to produce allergic inflammation begins to develop early during gestation. Although allergic inflammation is clearly dependent on multiple genetic traits, the final expression of an individual's genetic endowment is highly influenced by various environmental exposures. Among the most important environmental influences are the timing and intensity of allergen exposures, infections in early life, the home environment, animal exposure, and exposure to environmental pollutants. The developing immune system seems most pliable early in life, but new allergic responses can develop throughout life, even into late adulthood. Understanding the mechanisms by which early exposures influence the risk of atopic disease may ultimately allow the development of strategies for primary or secondary prevention of allergic diseases.