Allergy prevention. Interventions during pregnancy and early infancy.

The increase in allergic disease in western, industrialized countries has been phenomenal. Although the reasons for this increase are unknown, it is clear that the primary management of allergies is prevention. There is now significant epidemiologic data suggesting that a program designed and focused on prevention will have a significant impact on the development of allergies. These include not only environmental, but also dietary restrictions. There remain, however, several major problems. Firstly, it is not clear which subjects will respond best to a program focusing on either pre-or postnatal prevention. Secondly, the immunological mechanisms involved remain unclear. For example, it would be highly desirable to have a readout that monitors the improvement in allergen avoidance, other than clinical response. This review will focus on the immunological background of allergy prevention, including epidemiologic observations and thoughts for future potential allergy prevention.