Epidemiology of childhood food allergy.

Food allergy is a public health problem that affects nearly 6 million children in the United States. The extent to which children, families, and communities live with food allergies varies as much as the range of clinical symptoms associated with the disease itself. Food allergy is defined as the reproducible adverse event that elicits a pathologic immunoglobulin E (IgE)-mediated or non-IgE-mediated reaction. Once an allergic child ingests a specific food allergen, the reaction can result in clinical symptoms ranging from mild hives to life-threatening anaphylaxis.Not surprisingly, food allergies have been shown to limit social interactions and impair children's quality of life due to the ubiquity of food where children live, learn, and play. To ensure the safety of our children, the development of sound policy, clinical practice, and health programs must be informed by current research characterizing childhood food allergy at the population level. To set the stage for understanding the current evidence base, this article reviews: 1) epidemiology of childhood food allergy; 2) severity of symptoms; 3) geographic distribution of childhood food allergy; 4) tolerance; 5) economic impact of childhood food allergy; and 6) future directions in childhood food allergy epidemiological research.