Health and Fitness : What is a Food Allergy?

What Is Food Allergy?

Food allergy is an abnormal response to a food, triggered by the body’s immune system. There are several types of immune responses to food. The information on this Web site focuses on one type of adverse reaction to food, in which the body produces a specific type of antibody, called immunoglobulin E (IgE).

The binding of IgE antibodies to specific molecules in a food triggers the immune response. Read about what happens during an allergic response to food.

The response may be mild, or in rare cases it can be associated with the severe and life-threatening reaction called anaphylaxis.

If you have a food allergy, it is extremely important for you to work with your healthcare professional to learn what foods cause your allergic reaction. Learn about how healthcare professionals diagnose food allergy.

Sometimes, a reaction to food is not an allergy at all but another type of reaction called food intolerance.

Food Allergy Quick Facts

There are eight major food allergens in the United States: milk, egg, peanut, tree nuts (cashews, almonds, pecans, walnuts), soy, wheat, fish, and crustacean shellfish (lobster, crabs, shrimp).

In the United States, food allergy affects an estimated 5 percent of children under the age of 5 and an estimated 4 percent of people aged 5 and older.

The prevalence of food allergy increased by 18 percent from 1997 to 2007.

Estimated prevalence rates in the United States for individual food allergens include the following:

Peanut: 0.6 percent

Tree nuts: 0.4–0.5 percent

Milk and egg: no reliable data available from U.S. studies, but based on data obtained outside the United States, this rate is likely to be 1 to 2 percent for young children

All seafood: 0.6 percent in children and 2.8 percent in adults

Most children eventually outgrow milk, egg, soy, and wheat allergy. Outgrowing a childhood food allergy may occur as late as the teenage years.

Children are much less likely to outgrow peanut and tree nut allergy.

If someone has food allergy, he or she is more likely to have asthma or eczema.

A person is more likely to have a severe allergic reaction to food if he or she also has asthma or if he or she has previously had an anaphylactic reaction.

Allergic reactions to food can range from mild to life-threatening.

A person cannot tell how severe his or her next food-allergic reaction will be based on the severity of previous reactions.

Even with attempts to avoid food, accidental exposures leading to an allergic reaction do occur at a rate of nearly once per year in young children who are highly allergic.

Because of the high risk of allergic reactions to food, many people with food allergy are prescribed auto-injector epinephrine, which should be with them at all times.

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Source: NIH