Definition Anaphylactic shock, or anaphylaxis, 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 that a person has become very sensitive to. 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 the following:
Anaphylaxis is a medical emergency because it can lead to a blocked airway, shock, and death.
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. A medical bracelet that states what the person is allergic to should be worn at all times. It is very important to keep an unexpired adrenaline kit handy to be used in an emergency.
How is the disease diagnosed? The key to diagnosing anaphylaxis is an accurate medical history. The typical history is the rapid onset of signs and symptoms within a few minutes of being exposed to the offending agent. The physical examination may show redness or hives over much of the body, difficulty breathing, wheezing, and low blood pressure.
What are the long-term effects of the disease? Anaphylaxis can be fatal. After recovery from an episode, there are no long-term effects. However, an individual may experience worry and anxiety about a future attack.
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 treated by a Injection of adrenaline given under the skin or into the muscle. The dose can be repeated depending on how the person responds. Other drugs can be useful as well. These include diphenhydramine, aminophylline, or corticosteroids.
Oxygen and intravenous fluids are important in supportive care. A person's breathing must be watched very carefully. If breathing becomes difficult, a tube may need to be inserted into the person's mouth or directly into the throat to help him or her breath.
What are the side effects of the treatments? Medications used to treat anaphylaxis may have minor side effects. Diphenhydramine causes drowsiness and dry mouth. Adrenaline and aminophylline cause an increase in heart rate. However, these side effects are minimal when compared to the often-fatal outcome of anaphylaxis.
The use of a tube to breathe may cause coughing or sore throat after it is removed.
What happens after treatment for the disease? After treatment of anaphylaxis a person can recover fully.
How is the disease monitored? Monitoring requires the person to avoid the offending agent.
Author: Minot Cleveland, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
