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Primary Children's Hospital

Primary Children's Hospital
100 North Mario Capecchi Drive
Salt Lake City, Utah 84113-1100
(801) 662-1000
www.primarychildrens.org


Serious Allergic Reactions (Anaphylaxis)

What Is Anaphylaxis?

Anaphylaxis is a severe allergic reaction. Things that can cause allergic reactions are called allergens.

Anaphylaxis (pronounced: an-eh-fil-AK-siss) most often happens during allergic reactions to:

  • foods
  • insect stings
  • medicines
  • latex

Anaphylaxis can be scary. But being prepared will help you treat a reaction quickly.

What Are the Signs & Symptoms of Anaphylaxis?

Allergic reactions can cause:

  • trouble breathing
  • throat tightness or feeling like the throat or airways are closing
  • hoarseness or trouble speaking
  • wheezing
  • nasal stuffiness or coughing
  • nausea, belly pain, vomiting, or diarrhea
  • trouble swallowing
  • fast heartbeat or pulse
  • skin itching, tingling, redness, or swelling
  • hives
  • a feeling like something bad is about to happen
  • pale skin
  • passing out

Anaphylaxis can cause different symptoms at different times. It's considered anaphylaxis if someone has:

  • any severe symptoms, such as trouble breathing, repeated vomiting, passing out, or throat tightness
    or
  • two or more mild symptoms, such as hives and vomiting or coughing and belly pain

The person needs treatment right away.

How Is Anaphylaxis Treated?

Someone with anaphylaxis needs help right away. The reaction can get worse very quickly. So doctors usually want people with allergies to carry injectable medicine called epinephrine. Epinephrine enters the bloodstream and works quickly against serious allergy symptoms.

Doctors prescribe auto injectors. These should always be with the person with allergies, including at school, sports, jobs, and other activities. The auto injector is small and easy to use.

If you're prescribed epinephrine, the doctor will show you how to use it. Always have two auto injectors with you in case one doesn't work or you need a second dose.

Your doctor also might instruct you to take antihistamines in some cases. But always treat a serious reaction with epinephrine. Never use antihistamines instead of epinephrine in serious reactions.

What to Do if You Have Anaphylaxis

Give yourself epinephrine right away if you start to:

  • have trouble breathing
  • feel tightness in your throat
  • feel faint
  • have two or more milder allergic symptoms together (like hives with coughing)

Don't try to use an inhaler or antihistamine and wait to see what happens. Go straight for the epinephrine! Seconds count during anaphylaxis.

If you have signs of a serious allergic reaction:

  1. Use the epinephrine auto-injector right away. Then call 911. 
  2. Lay down with your legs raised while you wait for the ambulance.
  3. Go to the emergency room, even if symptoms improve after epinephrine. You must be under medical supervision for several hours. This is because a second wave of serious symptoms (called a biphasic reaction) often happens. You can get more treatment at the emergency room, if you need it.

What Else Should I Know?

Being prepared can help you stay safe:

  • Carry two epinephrine auto injectors with you at all times. Epinephrine can be a lifesaver.
  • Avoid the things you are allergic to.
  • Let friends, teachers, and coaches know about your allergies and how they can help you if you have a reaction.
Reviewed by: Larissa Hirsch, MD
Date reviewed: November 2019