Angioedema: differential diagnosis and treatment.

Conditions causing angioedema can be loosely classified as those with underlying C1-inhibitor deficiency or dysfunction and those that do not. Determining the root cause of symptoms and ruling out conditions that masquerade as angioedema help clinicians plan appropriate management. The various etiologies of angioedema have overlapping symptoms that can complicate the diagnosis. An awareness of features unique to a specific cause of angioedema will aid in the differential diagnosis. A thorough history may reveal a family history of episodic swelling, bouts of swelling associated with medication use, or swelling associated with certain foods or environmental allergens. Similarly, a history of symptom onset later in life is more common in acquired angioedema. The presence of urticaria suggests an allergic component. Treatment strategies have been devised for all forms of angioedema, although specific therapeutic targets may be unknown. Several medications directed at the underlying cause of symptoms in hereditary angioedema have been recently approved for use in the United States. Clinical symptoms, differential diagnosis, and management strategies for angioedema are reviewed in this article.