Anaphylaxis (say: "anna-full-ax-iss") is a life-threatening allergic reaction. It starts soon after you are exposed to something you are severely allergic to. You may have swelling, itching or a rash with itchy bumps (hives). Some people have trouble breathing, a tight feeling in their chest or dizziness. Some people feel anxious. Other people have stomach cramps, nausea or diarrhea. Some people lose consciousness (pass out). A person who has anaphylaxis needs immediate medical attention
Anaphylaxis symptoms may include one or more of the following:
These symptoms usually show up right after you are exposed to an allergen (see Causes & Risk Factors to learn more about allergens). The symptoms can be mild or severe. Be sure to tell your doctor if you think you’ve ever had a severe allergic reaction or symptoms of anaphylaxis, even if your symptoms were mild.
Anaphylaxis is most often caused by exposure to an allergen. Normally, when you are exposed to an allergen, your immune system produces antibodies to help you “fight” the allergen. These antibodies are the cause of normal allergy symptoms—normal allergy symptoms aren’t life threatening. However, sometimes your immune system can overreact to an allergen and cause a very severe allergic reaction—this can lead to anaphylaxis and is very dangerous.
Allergens and substances that may lead to anaphylaxis include the following:
Call 911 to get emergency medical help right away.
If the person having an attack has an emergency anaphylaxis kit with an EpiPen (epinephrine injector), give him or her the epinephrine injection right away. Then, make sure he or she still goes to the emergency room for follow-up. Epinephrine just buys the victim some time to get to emergency care.
An emergency anaphylaxis kit contains medicine to counteract your allergic reaction. This medicine is usually a drug called epinephrine that you inject into your arm or leg (or have a friend inject). Your doctor will prescribe a kit with the right dose of medicine and will teach you how to use it. Make sure your family, friends, and coworkers also know how to use the kit. Sometimes your doctor will tell you to keep an antihistamine, such as diphenhydramine (one brand name: Benadryl), in the kit too.
You should recover completely with treatment. Most people live a normal, full life. You can get back to your normal activities once you are feeling better. However, you should have someone stay with you for 24 hours after anaphylaxis to make sure another attack does not happen.
If you’ve had anaphylaxis, you need to be prepared for the possibility that you will have anaphylaxis again in the future. Talk to your doctor about how to minimize your risk for anaphylaxis in the future, and how to use your emergency medical kit.
The following are some ways to help prevent a reaction:
If you are at risk of anaphylaxis, keep an emergency anaphylaxis kit with you at all times. Make sure the people around you, such as your family and friends, know how to use it.
Written by familydoctor.org editorial staff