Food allergy is an immune system reaction that happens soon after eating a certain food. Even a tiny amount of the allergy-causing food can trigger symptoms such as digestive problems, hives or swollen airways. In some people, a food allergy can cause severe symptoms or even a life-threatening reaction known as anaphylaxis.

Food allergy affects an estimated 8% of children under age 5 and up to 4% of adults. While there’s no cure, some children outgrow their food allergies as they get older.