Angioedema is erroneously, frequently regarded as a “deep” hive, however it is a non-erythematous (not red), non-pruritic (not itchy) swelling of any “soft” tissue of the body i.e. eyelids, lips, tongue, genitals, joints, etc.).  It cannot be reproduced by injecting histamine under the skin, and does not respond to the administration of antihistamines. (They usually resolve spontaneously – with or without any treatment, within 96 hours.) The few biopsies studied do not show the same microscopic changes that are seen with hives (urticaria).

The confusion arises from the observation that angioedema does occur at times with hives (welts, urticaria), especially when the hives are caused by aspirin, ibuprofen [and other NSAIDs], and IgE-allergens.  More often AE occurs without hives, especially when triggered by the blood pressure medications known as ACE-inhibitors, or as part of a rare hereditary disease (Hereditary AngioEdema (HAE).   When no trigger is identifiable, the angioedema is considered idiopathic.

Vincent S. Beltrani, MD, FAAAAI

Associate Clinical Professor
Department of Dermatology, Columbia University
New York, New York
Associate Clinical Professor
Department of Allergy, UMDNJ
Newark, New Jersey