Overview, Causes, & Risk Factors

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 causes and risks of the disease?

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

  • aspirin and nonsteroidal anti-inflammatory drugs, such as ibuprofen
  • contrast agents, which are injected for some special X-ray tests
  • foods, such as nuts, berries, eggs, beans, seafood, grains, and chocolate
  • hormones, including insulin, methylprednisolone, and progesterone
  • latex rubber
  • local anesthetics, such as lidocaine and procaine
  • penicillin, cephalosporins, and other antibiotics
  • physical stimuli, including exercise and cold air
  • pollen from plants
  • venom from a snakebite
  • venom from spiders, yellow jackets, hornets, or honeybees
  • Symptoms & Signs

    What are the signs and symptoms of the disease?

    The symptoms of anaphylaxis may include:

  • abdominal distress and diarrhea
  • cough, sneezing, and nasal congestion
  • dizziness
  • nausea and vomiting
  • severe itching and hives all over the body
  • shortness of breath
  • swelling of the face or tongue
  • swelling over much of the body
  • tightness in the chest or throat
  • Diagnosis & Tests

    How is the disease diagnosed?

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

    Prevention & Expectations

    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.

    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.

    Treatment & Monitoring

    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:

  • antihistamines, such as diphenhydramine
  • bronchodilators, such as albuterol
  • corticosteroids, such as methylprednisolone
  • H2-receptor blockers, such as cimetidine
  • 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 often-fatal outcome of anaphylaxis.

    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 an Epi-Pen or an Ana-Kit. These are devices containing epinephrine to prevent anaphylaxis. The devices can be used by the person or a bystander to inject the medicine.

    How is the disease monitored?

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

    Article type: xmedgeneral