Anaphylaxis is a severe, potentially life-threatening allergic reaction.
Signs and symptoms include a rapid, weak pulse; a skin rash; and nausea and vomiting.
Common triggers include certain foods, some medications, insect venom, and latex.
Claudia Miranda / EyeEm / Getty Images
Anaphylaxis requires an injection of epinephrine and a follow-up trip to an emergency room.
If you don’t have epinephrine, you should probably go to an emergency room immediately.
If anaphylaxis isn’t treated right away, it can be fatal.
Anaphylaxis symptoms usually occur within minutes of exposure to an allergen.
Sometimes, however, it can occur a half-hour or longer after exposure.
Don’t wait to see if the symptoms go away.
If the person having the attack carries an epinephrine autoinjector (EpiPen), administer it right away.
This second reaction is called biphasic anaphylaxis.
Your immune system produces antibodies that defend against foreign substances.
This is good when a foreign substance is harmful, such as certain bacteria or viruses.
But some people’s immune systems overreact to substances that don’t normally cause an allergic reaction.
Allergy symptoms aren’t usually life-threatening, but a severe allergic reaction can lead to anaphylaxis.
Talk with your doctor about precautions to take when exercising.
If you don’t know what triggers your allergy attack, certain tests can help identify the allergen.
In some cases, the cause of anaphylaxis is never identified (idiopathic anaphylaxis).
Your doctor will want to rule out other conditions.
Do the following immediately:
Many people at risk of anaphylaxis carry an autoinjector.
Always replace epinephrine before its expiration date, or it might not work properly.
Using an autoinjector immediately can keep anaphylaxis from worsening and could store your life.
Be sure you know how to use the autoinjector.
Also, double-check the people closest to you know how to use it.
But you might take steps to prevent a future attackand be prepared if one occurs.
Developing an anaphylaxis emergency action plan can help put your mind at ease.
Then share your plan with teachers, baby sitters, and other caregivers.
check that school officials have a current autoinjector.
The best way to prevent anaphylaxis is to avoid substances that cause this severe reaction.
Keep an emergency kit with prescribed medications availableat all times.
Your doctor can advise you on the contents.
Be sure to alert all your doctorsto medication reactions you’ve had.
Stay calm when near a stinging insect.
Move away slowly and avoid slapping at the insect.
If you have food allergies, carefully read the labelsof all the foods you buy and eat.
Manufacturing processes can change, so it’s important to periodically recheck the labels of foods you commonly eat.
When eating out, ask how each dish is prepared, and find out what ingredients it contains.
Even small amounts of food you’re allergic to can cause a serious reaction.
Updated: 2017-02-14
Publication Date: 2000-07-10
