Angioedema

A Look at Angioedema

Angioedema
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Medical Specialties:

Allergy/immunology, Dermatology, Family practice, Internal medicine

Clinical Definition:

Angioedema is a non-pitting edema that affects the dermis and subcutaneous layers, most often involving the tongue, lips, face and throat, but also less commonly the genitalia and viscera, or organs. Edema can also affect the airway, a potentially life-threatening event. If angioedema is severe, emergency treatment to ensure an open, functioning airway is needed.

In Our Own Words:

Allergies, hives and certain kinds of angioedema are linked in that they involve reactions to histamine. However unlike hives, angioedema is a deeper swelling that occurs below the surface of the skin, usually around the lips and eyes but sometimes affecting other areas or the body. An allergic reaction to either food or medicine or an allergic reaction to an insect sting is the typical trigger.

Hereditary angioedema is a rare genetic condition involving recurrent angioedema that is not associated with itching or hives.

Sometimes the cause of angioedema is unknown.

In all cases, if angioedema affects the tongue, throat or airways, emergency treatment is crucial to ensure the airway is open and breathing is not compromised.

More Information About Angioedema-Urticaria

Urticaria, which is a superficial skin inflammation that results in hives or wheals, often accompanies angioedema, which is a deeper swelling.

Thus, these conditions conflate and can essentially be considered one clinical entity.

When urticaria and angioedema last fewer than 6 weeks, they're considered acute. Attacks that last longer than 6 weeks are chronic.

Most cases of urticaria-angioedema are idiopathic, meaning that the cause is unknown.

When we do know the cause of these conditions, it mostly has to do with the ingestion of shellfish, fish, milk products, peanuts, medications and so forth. Inhalational causes of urticaria-angioedema are rarer and typically occur in the context of seasonal allergies as well as inhalation of animal dander or mold.

Here are some symptoms typically experienced during an attack of angioedema-urticaria:

  • burning, painful, swollen and itchy areas;
  • discolored patches on the hands, feet and genitals;
  • hoarseness, tightness and swelling of the throat (medical emergency);
  • red welts commonly located near the eyes or lips but can also occur on the feet, hands and inside of the throat.

Here is how angioedema-urticaria is typically treated:

  • avoidance of triggers such as certain foods;
  • antihistamine medications, such as chlorpheniramine or diphenhydramine (Benadryl);
  • second-generation antihistamines like loratatdine (Claritin);
  • addition of histamine antagonists, such as cimetidine, famotidine, and ranitidine, when antihistamines are inadequate;

Of note, when treating angioedema-urticaria, second-generation antihistamines are usually preferred to classical antihistamine medications, like Benadryl, because these second-generation antihistamines are nonsedating and don't cause people to become sleepy.

Sources:

Lewis, LM. "Angioedema: Etiology, Pathophysiology, Current and Emerging Therapies." Jourrnal of Emergency Medicine. 2013; 13 (online Aug. 28). [looks like no issue number yet] Accessed Sept. 2013.

The Cleveland Clinic. "Urticaria (Hives) and Angioedema." Diseases & Conditions. Mar. 2008. Accessed Sept. 2013.

University of Maryland Medical Center. "Angioedema." Conditions. June 2012. Accessed Sept. 2013.

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