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anaphylaxis

Alternative Names
anaphylactic shock

Definition

Anaphylaxis, or anaphylactic shock, is a severe allergic reaction that affects the whole body. It can lead to death.

What is going on in the body?

Anaphylaxis is a response to a substance to which a person has become very sensitive. An antibody called IgE causes cells to release a variety of substances called mediators. These mediators are responsible for the allergic reaction. They affect blood vessels, smooth muscle, and inflammatory cells all over the body.

What are the signs and symptoms of the disease?

The symptoms of anaphylaxis may include:

What are the causes and risks of the disease?

Anaphylaxis is often an allergic reaction to one of the following:

What can be done to prevent the disease?

The best way to prevent anaphylaxis is to avoid any substance that has caused a severe reaction in the past. Persons who are sensitive to insect bites or bee stings should avoid walking with bare feet.

How is the disease diagnosed?

Anaphylaxis is usually diagnosed with a medical history and physical exam.

What are the long-term effects of the disease?

Anaphylaxis can be fatal. After recovery from an episode, there are no long-term effects.

What are the risks to others?

Anaphylaxis is not contagious and poses no risk to others.

What are the treatments for the disease?

Anaphylaxis is a medical emergency. The emergency medical system should be contacted immediately. Anaphylaxis is treated by a shot of epinephrine given under the skin or into the muscle. The dose can be repeated depending on how the person responds.

Other medicines used to treat anaphylaxis include the following:

Oxygen and intravenous fluids are given. If breathing becomes difficult, a tube may need to be inserted to help the person breath.

What are the side effects of the treatments?

Many of the medicines used to treat anaphylaxis cause a rapid heartbeat and increased blood pressure. However, these side effects are minimal when compared to the likely fatal outcome of anaphylaxis without treatment.

What happens after treatment for the disease?

Someone who experiences anaphylaxis should work with the healthcare provider to identify his or her triggers. A medical bracelet that states what the person is allergic to should be worn at all times. People with severe allergies may carry either a portable syringe containing epinephrine (i.e., Epi-Pen, Epi-Pen Jr.). These devices contain epinephrine to prevent anaphylaxis and can be injected quickly into the thigh by ther person himself or a bystander.

How is the disease monitored?

Anaphylaxis is a medical emergency. The emergency medical system should be contacted immediately if symptoms recur.


Author:Minot Cleveland, MD
Date Written:03/14/00
Medical Review:Thomas O'Brien, MD
Date Written:9/14/2006
Reviewer:Reginald Finger, MD
Date Reviewed:9/15/2006
Contributors
Potential conflict of interest information for reviewers available on request