Please note: This information was current at the time of publication but now may be out of date.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. 

brand logo

Am Fam Physician. 2023;108(2):online

Related article: Food Allergies: Diagnosis, Treatment, and Prevention

What are food allergies and what can cause them?

Food allergies happen when your body has a bad reaction to something you eat. This is not food poisoning. Babies and children are more likely to be allergic to peanuts, cow's milk, tree nuts (like pecans and walnuts), eggs, soy, and wheat. You can develop food allergies at any point in your life. If you have food allergies as a child, you might outgrow most of them by the time you become an adult. You might not outgrow allergies to fish, peanuts, shellfish, and tree nuts.

What should I look for?

Allergy symptoms usually start in a few minutes to hours after eating foods to which you are allergic. You may have:

  • Itching or tingling feeling in your mouth, lips, or tongue

  • Swelling of face, mouth, lips, or tongue

  • Skin rash or hives

  • Diarrhea

  • Sick feeling in your stomach or throwing up

  • Stomach cramps

  • Trouble breathing

  • Coughing or wheezing

  • Dizziness or feeling light-headed

If you have swelling of your face, tongue, mouth, or throat or trouble breathing, call 911 right away!

The most severe allergic reaction is called anaphylaxis (AN-uh-fuh-LAK-sis), which can kill you. You should seek emergency care immediately because this type of reaction can cause trouble breathing, low blood pressure, and shock.

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.

  • Keep a list of the foods you eat and any symptoms you have after eating them.

  • Talk to your doctor about your concerns and tell them your symptoms. Your doctor may do blood tests.

  • Your doctor might have you see an allergy specialist who might do other tests, like a skin test or food challenge, to see if you react to certain foods. This test is done in an office where you can be treated if you have a severe reaction.

  • Do not eat the food you think is causing the problem until you see a doctor and they give further instructions.

Is there a treatment for food allergy?

There is no cure for food allergies. Some medicines may help if you have a mild reaction. To prevent future allergic reactions, do not eat the food that is causing the problem. You can lower your chance of an allergic reaction by doing these things:

  • Your doctor may tell you to start your baby between four and six months of age on foods that can cause allergies. This can decrease the chance of your child getting food allergies.

  • Read 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).” Bring the food labels to your doctor's office so you can ask any questions.

  • When you eat at a restaurant, ask what is in your food if you are not sure.

  • Be aware of foods that can cause allergy symptoms. For example, if you are allergic to shrimp, eating lobster or crab also may cause symptoms.

  • Wash your hands after touching any food to which you or anyone in your family is allergic.

  • Wear a medical alert bracelet or necklace that says what foods you are allergic to if you have a severe reaction.

  • Carry an epinephrine (EP-uh-NEF-rin) shot with you if you have a severe allergic reaction. Your doctor or pharmacist can show you how to use it. You can also learn how to use an epinephrine pen by watching the video at

For more information on food allergies, go to

Continue Reading

More in AFP

More in PubMed

Copyright © 2023 by the American Academy of Family Physicians.

This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.  See permissions for copyright questions and/or permission requests.