Angioedema and Swelling Syndromes

Angioedema is characterized by the sudden onset of swelling of the skin, subcutaneous tissue, or mucous membranes. It may or may not occur with urticaria/hives. The swelling can involve the extremities, bowels, genitalia, trunk, face, tongue, or larynx. This swelling is usually short-lived and dissipates over 1-3 days (with the exception of hereditary angioedema [HAE], which may persist longer). Although swelling is usually self-limiting, involvement of the upper airways and gastrointestinal tract can lead to life- threatening asphyxia and intense abdominal pain, vomiting, and diarrhea, respectively.

Allergic angioedema is a hypersensitivity to food, drugs, insect stings, or other substances in the environment. Sometimes the causes are unknown.

Nonallergic angioedema (egs. hereditary, drug-induced, acquired) usually is mediated by another substance called bradykinin. As an example, angioedema can occur in 0.1% to 0.5% of patients who receive ACE inhibitors, often prescribed to treat high blood pressure.

What is hereditary angioedema?

In hereditary angioedema, approximately 40% experience their first episode before age 5 years, and 75% present before age 15 years. The swelling in childhood may be mild and worsen during adolescence. Some individuals may have no symptoms, but still have the genetic mutation associated with this disorder called C1NH mutation. They may be diagnosed after family members are diagnosed.

Treatment of a reaction can be complicated. This disorder is unresponsive to epinephrine, antihistamines and corticosteroids. Options may include medications that block the immunological reactions, such as medicines that inhibit plasma kallikrein, C1 esterase, or bradykinin. Prophylaxis, especially prior to a major procedure, may be indicated.

If you have had angioedema, an allergist can help identify the cause and recommend the appropriate treatment.