Acquired angioedema.

Acquired angioedema (AAE) is a rare disorder that has been categorized into two forms, AAE-I and AAE-II. AAE-I is associated with other diseases, most commonly B-cell lymphoproliferative disorders. AAE-II is defined by the presence of an autoantibody directed against the C1-inhibitor molecule. Differentiating AAE-I from AAE-II is vital because different therapeutic interventions are required for each type. This review summarizes the clinical aspects, pathophysiology, and management of AAE compared with the types of hereditary angioedema.