Hereditary angioedema in a family presenting as transient periarthritis.

Hereditary angioedema (HAE) is a rare condition known to cause episodic, self-limiting, nonpruritic, nonpitting edema that involves skin and visceral organs. It may affect any external body surface including face, extremities, and genitalia. Most commonly involved viscera are gastrointestinal and respiratory systems. Patients may have severe abdominal pain because of edema of the bowel wall. This disease can cause life threatening laryngeal edema if it involves the airway.We describe a patient with HAE who was initially diagnosed with arthritis after she had recurrent edema around her peripheral joints. Diagnosis of HAE in her led to the same diagnosis in her sister and her father. HAE should be considered in the differential diagnosis of recurrent attacks of periarticular swelling.