What is anaphylactic shock?
Anaphylactic shock (aka anaphylaxis) is a severe allergic reaction that occurs within minutes of exposure to an allergycausing substance. Only certain individuals are unfortunate to be prone to this potentially fatal reaction.
How does it occur?
After contact with an allergen, blood vessels leak fluid into the area around them. As a result, blood pressure may drop suddenly. Because there is less blood flow, less oxygen reaches the brain and other vital organs. Since these organs cannot function properly, the body goes into shock. In addition, the body responds to the allergen by releasing chemicals such as histamines that cause swelling of the skin, a red rash, and severe itching. Complications of anaphylactic shock can include brain damage, kidney failure, and/or death.
What can cause anaphylactic shock?
Substances that can cause anaphylactic shock include:
- food and food additives (ex: peanuts, shellfish)
- insect stings and bites
- agents used in immunotherapy
- medications (ex: drugs used as local anesthetics) or vaccines (ex: anti-tetanus serum)
- in rare cases, pollens, dust, other substances in the air, or pet dander.
What are the symptoms?
Symptoms of anaphylactic shock include:
- feeling faint
- anxiety or a sense of “impending doom”
- difficulty breathing, including wheezing
- nausea and vomiting and/or stomach pain
- swelling of lips, tongue, or throat (angioedema)
- itchy, blotchy, raised rash called hives (urticaria)
- pale, cool, damp skin
- drowsiness, confusion, or loss of consciousness
How is it diagnosed?
If you are conscious, the doctor will ask you about contact with substances to which you may be allergic. Then your doctor will examine you for symptoms of shock by checking your vital signs. We may recommend tests to determine the cause of your condition and its seriousness.
How is it treated?
Look for a medical card or Medic Alert bracelet which has information about allergies.
- Treating yourself: If you have a known severe allergy, such as to a bee sting or a food such as peanuts, which you might accidentally come in contact with, the physician will recommend carrying an injection kit. With the kit you can give yourself a shot of medicine to counteract the allergic reaction. If you are waiting for help to arrive, lie down and raise your legs above your chest to increase the blood flow to your vital organs.
- Treating someone in anaphylactic shock: Anaphylactic shock requires emergency medical attention. If you suspect someone is in shock, call 911 and ask for paramedics and an ambulance. Check to see if the person has stopped breathing or if his or her heart has stopped beating. If so, perform cardiopulmonary resuscitation (CPR) until the person is breathing and has a pulse or until paramedics arrive. Next, make sure the person is lying down comfortably. If the person has a clear airway (has nothing in his or her mouth), raise the person's legs above the chest to increase blood flow to the vital organs. By all means, if the patient is conscious, ask them if they keep an injection kit and administer it if it is absolutely clear that it is indeed an allergic reaction.
How long will the effects last?
How long the effects of anaphylactic shock last will depend on how quickly the person receives treatment. The symptoms may last from a few minutes to several hours. Without immediate medical treatment, the result can be death, but early treatment can help prevent serious complications.
How can I take care of myself?
Do not delay seeking help. If you have had a previous severe allergic reaction, you may want to:
- Ask your doctor to prescribe several kits to treat anaphylaxis early and review the instructions with you. Keep tabs on the expiration date on the kits. Review the instructions until you are familiar with them. Carry one kit with you and keep one at home.
- Be prepared to give yourself an injection in case of an emergency. Think of this injection as something you can do to keep yourself alive long enough to reach medical attention.
- Wear a Medic Alert bracelet that warns of your allergy and tells what to do in case of an emergency. Inform your friends and co-workers of these measures.
- Avoid foods, chemicals, drugs, and other substances that have caused allergic reactions. For example, if shrimp causes an allergic reaction, don't eat shrimp or shrimp sauce. When eating at a strange place, be sure to ask about the ingredients used in the foods you are eating.
- Consider having immunotherapy in which your immune system is gradually exposed to the toxic substance to make it less harmful to you. Immunotherapy is very effective for insect allergies but not for food or drug allergies.
- Always tell your doctor and dentist about any drug allergies you have before they prescribe medication. Ask them to prescribe another drug as soon as possible and ask for a list of related drugs. Also tell your pharmacist about any drug allergies.
- Check labels before taking over-the-counter medicines or eating foods if you have drug or food allergies.
How can I help prevent anaphylactic shock?
Learn what substance causes your reaction and avoid that substance. Ask your doctor about desensitization treatments, which can help in some cases.
PDF for additional information.