Angioedema refers to the swelling that occurs in the tissue just below the skin. Angioedema is similar to urticaria (hives), except it occurs deeper in the skin. The swellings, known as welts, usually appear around the eyes and mouth. They may also be present on the hands, feet and throat. Angioedema can develop in anywhere from a few minutes to a few hours.
Angioedema is generally caused by an allergic reaction to either a food or medication. When an allergic reaction occurs, the immune system releases histamine and other chemicals into the bloodstream, causing allergic symptoms such as angioedema to occur. Angioedema could also be a sign of an underlying immune disorder like leukemia or Hodgkin's disease.
Angioedema that does not affect breathing is usually harmless and goes away in a few days. In most cases, angioedema does not leave any lasting marks, even without treatment. However, complications can range from dysphonia (difficulty speaking) or dysphagia (difficulty swallowing) to respiratory distress, complete airway obstruction and death.

Related Terms

Allergic angioedema, allergies, allergic reaction, anaphylaxis, angioneurotic edema, atrophedema, Bannister disease, Bannister's disease, circumscribed edema, dysphonia, dysphagia, edema, giant hives, giant urticaria, giant wheals, hives, hymenoptera envenomations, idiopathic angioedema, Milton disease, Milton's disease, periodic edema, Quincke disease, Quincke edema, Quincke's disease, Quincke's edema, urticaria, urticaria gigans, urticaria gigantea, urticaria tuberosa, urticarial eruptions.

types of angioedema

Hereditary angioedema (HAE) is genetic and tends to recur. This inherited form of angioedema is related to low levels or abnormal functioning of certain blood proteins (C1 inhibitors). These inhibitors help regulate immune system functions.
Acquired angioedema (AAE) is not genetic. It is characterized by painless, non-pitting, non-pruritic swelling of the skin. This form of angioedema occurs as a reaction to histamine or other chemicals in the blood. This form of angioedema is often, although not always, the result of an allergic reaction.
Angioedema-eosinophilia syndrome causes a fever, hives or itchiness. This form of angioedema is characterized by a high leukocyte count, muscle pain, weight gain or decreased urination.

angioedema and urticaria

Angioedema and urticaria are different manifestations of the same pathologic process. In both conditions, postcapillary venule inflammation results in fluid leakage and edema (swelling). However, angioedema involves vessels in the layers of the skin below the dermis, while urticaria is localized to the superficial portion of the dermis.
The subdermal source of angioedema results in well-demarcated, localized, non-pitting edema. Urticaria is characterized by well-circumscribed wheals with raised erythematous borders and central blanching.
Angioedema and urticaria can occur together or separately. Recurrent episodes of one or both conditions for less than a six-week period are considered acute, whereas longer-lasting outbreaks are considered chronic.