Angioedema

Definition:
The development of large welts below the surface of the skin, especially around the eyes and lips. The welts may also affect the hands, feet, and throat. The condition is associated with allergies and histamine release.

Alternative Names:
Angioneurotic edema; Swelling - eyes

Causes, incidence, and risk factors:
Angioedema is a swelling similar to urticaria (hives), but the swelling is beneath the skin rather than on the surface. There seems to be a hereditary tendency toward the development of both angioedema and hives (see hereditary angioedema). Angioedema is associated with the release of histamine and other chemicals into the bloodstream, which is part of the allergic response.

Common allergens include:
  • medications
  • foods (such as berries, shellfish, fish, nuts, eggs, milk, and others)
  • pollen
  • animal dander (scales of shed skin)
  • insect bites
  • exposure to water, sunlight, cold or heat
  • emotional stress
Hives and angioedema may also occur after infections or illness (including autoimmune disorders, leukemia, and others).
Symptoms:
  • sudden development of wheals or welts
    • usually located on the eyes and mouth, but may also occur on the hands and feet or in the throat
    • red
    • itching or painful
    • blanch and swell if irritated
    • deep
  • localized edema (eyes and mouth appear swollen)
  • abdominal cramping
  • difficulty breathing
  • chemosis (swollen conjunctiva)
Signs and tests:
The diagnosis is primarily based on the appearance of the skin and a history of exposure to an irritant/allergen. There may be stridor (crowing sound when inhaling) if the throat is affected. Rarely, allergy testing may be performed to determine the causative allergen.
Treatment:
Mild symptoms may not need treatment. Moderate to severe symptoms may need treatment. Difficulty breathing or stridor indicates an emergency condition.

Self-care includes cool compresses or soaks to the area to provide pain relief and reduce symptoms.

Medications to reduce the allergic response and associated symptoms include antihistamines, adrenaline (epinephrine), terbutaline, cimetidine, corticosteroids, sedatives, and tranquilizers.

For an emergency condition, protect the airway (see breathing difficulties - first aid). At the hospital, there may be a need for intubation (placement of a tube in the throat to keep the airway open).

To prevent recurrence of angioedema avoid irritating the affected area, avoid known allergens, and avoid temperature extremes. See also allergic reactions.
Expectations (prognosis):
Angioedema that does not affect the breathing may be uncomfortable, but it generally is harmless and resolves itself in a few days.
Complications:
Calling your health care provider:
Call your health care provider if angioedema is severe and does not respond to treatment.

Go to the emergency room or call the local emergency number (such as 911) if difficulty breathing, wheezing, stridor, or fainting occurs with an episode of angioedema.
Prevention:
Avoid known allergens and don't take medications that are not prescribed for you.

Review Date: 11/12/2001
Reviewed By: Michael Lehrer, M.D., Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.
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