Anaphylaxis
Pronounced: ANNA-fill-AX-is
(Anaphylactic Reaction)
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
Anaphylaxis is a severe, sometimes life-threatening, allergic reaction. The reaction includes hives, low blood pressure, and breathing difficulties. Anaphylaxis is extremely rare.
Causes
Substances that cause anaphylaxis are often called allergens or triggers. Common triggers include:
- Medications, including antibiotics, seizure medications, and muscle relaxants
- Insect stings or bites
- Vaccines
- Injected dyes used in some types of X-rays
- Foods and food additives, especially eggs, peanuts, seafood, cow's milk, soy, and sulfites
- Blood products
- Latex products (gloves, medical tubing, dental dams, condoms)
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
- Previous mild allergic reaction to the substances listed above
- History of eczema, hay fever, or asthma
- Children who have spina bifida and urogenital defects
Symptoms
The symptoms of anaphylaxis usually occur within minutes after exposure to an allergen. Symptoms may include:
- Hives and itching
- Swelling, redness, stinging or burning, especially of the face, mouth, or hands
- Lightheadedness, caused by a drop in blood pressure
- Obstruction of the nose, mouth and throat
- Severe respiratory distress
- Chest tightness, shortness of breath, wheezing
- Nausea, vomiting, cramping, diarrhea
- Heart arrhythmias
- Convulsions
- Shock
Diagnosis
Diagnosis of anaphylaxis is based on the symptoms. The doctor will suspect anaphylaxis if you have the symptoms and have been exposed to a likely allergen.
Treatment
Anaphylaxis is a medical emergency that requires immediate medical treatment, including:
Epinephrine (Adrenaline) Injection – makes blood vessels contract, relaxes the airway, stops itching and hives, and relieves gastrointestinal cramping.
Other medications – aminophylline, cortisone drugs, or antihistamines may be given after the epinephrine to help prevent the return of acute symptoms.
Cardiac measures – oxygen, intravenous (IV) fluids and cardiac monitoring will ensure that the heart, lungs, and blood pressure remain stable. Severe anaphylaxis may require mechanical ventilation, until swelling is brought under control.
Prevention
Avoiding substances that trigger anaphylaxis is the best prevention. In addition:
- Allergy shots can decrease the risk of anaphylaxis and reduce the severity of the reactions.
- Wear a Medic-Alert bracelet stating your allergies.
- Tell your doctor or dentist about your allergies before taking any medication. When possible, ask that medications be taken as a pill. Allergic reactions can be more severe with injected medications.
- Keep an anaphylaxis kit (Ana-Kit, Epi-Pen) with you at home, work, in the car, and when you travel. Be sure family and friends know how to use the kit, too.
- Make sure the school nurse knows about any allergies your child has.
- If allergic to insect stings, wear protective clothing when outside.
- Always remain in the doctor or dentist's office 15 minutes after receiving an injection. Report any symptoms immediately!
Organizations
Food Allergy and Anaphylaxis Network
http://www.foodallergy.org
American Academy of Allergy, Asthma and Immunology
http://www.aaaai.org
SOURCES:
Anaphylaxis. Emedicine, May 2, 2001.
Last reviewed "Allergy and allergic diseases." New England Journal of Medicine, January 11, 2001. by Medical Review Board
