occur when the body's immune system overreacts to substances in food you have
eaten, triggering an
allergic reaction. Food allergies are more common in
young children than in adults.
Milk, eggs, peanuts, tree nuts, fish, shellfish, wheat, and soy cause
most problems in children. Some babies are so sensitive to these
foods that if the offending food is eaten by the mother, drinking her breast
milk can cause a reaction. Most children outgrow allergies to eggs, milk,
wheat, and soy.
nuts, fish, and shellfish cause most of the allergic reactions in teens and
adults. Adults typically remain allergic to the food for life.
Food allergies are most common in people who are
atopic, meaning they have an inherited tendency to
have allergic conditions. These people are more likely to have asthma, various
allergies, and a skin condition called
atopic dermatitis. Asthma can make the reaction to a food more severe.
If you are highly
sensitive to a certain food, you may have an allergic reaction simply by
being near where the food was prepared or served.
is an abnormal immune system reaction to gluten, a protein found in grains like wheat and rye. It damages the small intestine so that it can't do a good job of absorbing nutrients from your food. For more information, see the topic
Many people, but not all people, are allergic to foods
that are similar or somehow related. This is called cross-reactivity. For
example, if you are allergic to shrimp, you may also be allergic to other
shellfish, like crab or lobster. If you are allergic to peanuts, you may be
allergic to other members of the legume family, such as peas and beans. You don't need to stop eating a cross-reactive food if you show no signs of an allergic reaction to it.
Oral allergy syndrome is a type of
cross-reactivity. With this syndrome, people who have pollen allergies (such as a
grass allergy) may develop itching, redness, and swelling of the lips and mouth
when they eat fruits or vegetables that contain a protein that reacts with the
pollen. These symptoms usually resolve quickly and do not involve other parts
of the body.