About Anaphylaxis

Learn about the causes of anaphylaxis, a severe and potentially life-threatening allergic reaction, from Food Allergy Research & Education (FARE).

If you believe you or your family member may be experiencing anaphylaxis, inject epinephrine immediately and call 911.

Anaphylaxis (pronounced an-uh-fil-LAX-is) is a severe, potentially life-threatening allergic reaction. Symptoms can affect several areas of the body, including breathing and blood circulation.

Causes of Anaphylaxis

Food allergy is the most common cause of anaphylaxis, although several other allergens—such as insect stings, medications or latex—can be potential triggers. Rarely, anaphylaxis is caused by exercise. Another uncommon form can occur when a person exercises soon after eating a problem food. It is very rare for anaphylaxis to occur without an identifiable trigger.

In the U.S., eight foods account for the majority of food allergy reactions: milk, egg, peanuts, tree nuts, soy, wheat, fish and shellfish. But any food may cause anaphylaxis. People who have both asthma and a food allergy are at greater risk for anaphylaxis.

Preventing and Treating Anaphylaxis

The only way to prevent anaphylaxis is to completely avoid the problem food. Researchers are working on preventive therapies; learn about current research.

Epinephrine (a synthetic form of adrenaline) is a medication that can reverse the severe symptoms of anaphylaxis. It is available as a self-injectable shot, also known as an epinephrine auto-injector. People with a prescription can carry and use this device if needed.

Epinephrine is a highly effective medication for anaphylaxis, but you must administer it promptly for it to work as intended. Delays can result in death in as little as 30 minutes.

Always take the treated individual to the emergency room for further evaluation. Someone who has received epinephrine may still need more treatment for the allergic reaction. Do this even if you gave epinephrine immediately and symptoms seem to subside.

Anaphylaxis Tips for People with Food Allergies

Vigilance is your first line of defense against anaphylaxis.

  • Learn all you can about avoiding allergens.
  • Read food labels carefully and don’t hesitate to ask questions when eating food you haven’t prepared yourself.
  • Have your medication with you wherever you go.
  • Talk to your allergist about when and how to use emergency medications.
  • Make sure your prescriptions are up-to-date. Refill them as they expire.
  • Consider wearing medical identification (such as bracelets or other jewelry).
  • Don’t hesitate to use expired epinephrine if that is all you have available—then call 911.
  • Don’t wait to see if your anaphylactic symptoms will improve! Use your emergency medications as prescribed, and don’t delay giving epinephrine. The risks from the allergic reaction far outweigh any risks from the medication.
  • Get to an emergency room for evaluation and further treatment right away—even if your medication has stopped the reaction.
  • Don’t take chances by eating a problem food. Epinephrine is not a foolproof treatment.

Learn more about how to recognize and respond to anaphylaxis with this free training. 

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