Food allergy is an abnormal response to a food triggered by the body’s immune system. Food allergy refers to a particular type of response of the immune system in which the body produces what is called an allergic, or IgE, antibody to a food. (IgE, or immunoglobulin E, is a type of protein that works against a specific food.) Allergic reactions to food can cause serious illness and, in some cases, death. Therefore, if you have a food allergy, it is extremely important for you to work with your healthcare provider to find out what food(s) causes your allergic reaction. Sometimes, a reaction to food is not an allergy at all but another type of reaction called “food intolerance.” Food intolerance is more common than food allergy. The immune system does not cause the symptoms of food intolerance, though these symptoms may look and feel like those of a food allergy.

Food allergy affects up to 6 to 8 percent of children under the age of 3 and close to 4 percent of adults. If you have an unpleasant reaction to something you have eaten, you might wonder if you have a food allergy. One out of three people either believe they have a food allergy or modify their or their family’s diet. Thus, while food allergy is commonly suspected, healthcare providers diagnose it less frequently than most people believe.