Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. 

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Am Fam Physician. 2012;86(1):online

See related article on food allergies.

What are food allergies? What foods can cause them?

Food allergies occur when your body has a bad reaction to something you’ve eaten. This is not food poisoning. Foods that commonly cause allergies vary slightly by age. Children and infants are more likely to be allergic to eggs, milk, peanuts, soy products, tree nuts (such as walnuts), and wheat. Adults are more likely to be allergic to fish, peanuts, shellfish, and tree nuts. If you have food allergies as a child, there’s a good chance you’ll outgrow most of them by the time you become an adult. But, you can develop food allergies at any point in your lifetime.

What should I watch for?

Allergy symptoms usually happen within a few minutes to hours of eating food you’re allergic to. You may get an itching or tingling feeling in your mouth, or you may develop hives or a skin rash. You may throw up, or you may have diarrhea, cramps, or trouble breathing. A really severe allergy could cause anaphylaxis (AN-uh-fuh-LAK-sis). This is a life-threatening condition that can cause you to have trouble breathing and low blood pressure or shock, and often requires emergency care.

How do I know if I have a food allergy?

There are several ways to see if the problems you are having might be due to a food allergy. These include:

  • Listing the foods you eat and any reactions you have after eating. (This is called a food diary.)

  • Having your doctor do blood tests.

    (However, these tests do not prove that you have a food allergy.)

  • Having an allergist do a special test, called a food challenge, to see if you have a reaction to certain foods. This test is done in an office or in the hospital, where you can be treated if you have a severe reaction.

  • Not eating the food you think is causing the problem to see if you still have symptoms.

Is there a treatment for food allergy?

There is no cure for food allergies. Some medicines may help if you have a mild reaction, but symptoms usually go away by themselves.

The best way to stop reactions is to avoid the food that’s causing the problem. Other steps you can take to reduce your allergic reaction, include:

  • Wearing a medical alert bracelet or necklace that indicates what foods you are allergic to.

  • Reading food labels carefully. Check the ingredient list for any foods that may cause allergies. Look for phrases like “This product may contain trace amounts of (food),” or “This product is made at a facility that uses (food).” If you have trouble understanding certain food labels, bring them to your doctor’s office so you can go over the labels together. Ask about what is in your food at a restaurant if you are not sure.

  • Being aware of foods that can cross-react and trigger allergy-like symptoms. For example, if you are allergic to shrimp, eating lobster or crab may cause similar symptoms.

  • Washing your hands after handling any food you or anyone in your family is allergic to.

  • Carrying an epinephrine pen with you. This is a device you can use if you have a severe allergic reaction. Your doctor can show you how to use it. You can also learn how to use an epinephrine pen at

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