If you are having any symptoms or have any questions, please call 811 to speak with a registered nurse 24 hours a day.

OVERVIEW

What is anaphylaxis?

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.

SYMPTOMS

What are the symptoms of anaphylaxis?

Anaphylaxis symptoms may include one or more of the following:

Hives, rash, or itchy skin
Pale skin, or skin that is red and warm (flushed)
Swelling in the mouth or throat, or of another body part
Wheezing or trouble breathing
A tight feeling in the chest
Dizziness
Fainting
A feeling of anxiety
Nausea, vomiting, or diarrhea

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 healthcare provider if you think you’ve ever had a severe allergic reaction or symptoms of anaphylaxis, even if your symptoms were mild.

CAUSES & RISK FACTORS

What causes anaphylaxis?

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:

Foods such as shellfish, nuts, peanuts, eggs, and fruits
Medicines such as antibiotics, aspirin, over-the-counter pain relievers (such as ibuprofen), allergy shots, and contrast dye for imaging procedures
Latex or rubber found in surgical gloves, medical supplies, and many products in your home
Insect stings, especially from bees, wasps, hornets, yellow jackets, sawflies, and fire ants

TREATMENT

What do I do if I have or someone I know has a severe allergic reaction?

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 them the epinephrine injection right away. Then, make sure they still go to the emergency room for follow-up. Epinephrine just buys the victim some time to get to emergency care.

What is in an emergency anaphylaxis kit?

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 healthcare provider 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 healthcare provider will tell you to keep an antihistamine, such as diphenhydramine (one brand name: Benadryl), in the kit too.

What can I expect after anaphylaxis?

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. Contact your healthcare provider about how to minimize your risk for anaphylaxis in the future, and how to use your emergency medical kit.

PREVENTION

How do I prevent anaphylaxis?

The following are some ways to help prevent a reaction:

If you have had anaphylaxis, make sure your healthcare provider and dentist know so that it is recorded on your medical chart. Tell them what you are allergic to, if you know.
If you are allergic to insect stings, wear protective clothing and insect repellent when you’re outside.
Avoid handling or eating foods you are allergic to. Even tiny amounts mixed by accident into your food can cause a reaction. Read the ingredient list on any packaged foods you are going to eat.
Wear or carry a medical alert bracelet, necklace or keychain that warns emergency medical technicians (EMTs) and healthcare providers that you are at risk for anaphylaxis.
Ask your healthcare provider if you need desensitization shots. If you have had anaphylaxis because of a bee or wasp sting, desensitization shots are almost always a good idea.
Ask your healthcare provider if there are other things you also might be allergic to.

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.

QUESTIONS TO ASK YOUR HEALTHCARE PROVIDER

I have an allergy. Could I be at risk for anaphylaxis?
What should I have in my anaphylaxis kit?
Do I need to wear a medical alert bracelet? Where do I get one?
If I’ve had one anaphylactic reaction, am I at greater risk for another one?
How do I make sure that all members of my health care team know about my risk for anaphylaxis?

FOR MORE INFORMATION

Health Canada
https://www.canada.ca/en/health-canada/services/healthy-living/your-health/medical-information/severe-allergic-reactions.html

Food Allergy Canada (formerly known as Anaphylaxis Canada)
http://foodallergycanada.ca/

Sources

A Practical Guide to Anaphylaxis by TW Tang, M.D. (10/01/03, http://www.aafp.org/afp/20031001/1325.html )