Differential diagnosis of angioedema.

There are many conditions that may present with swelling that mimics angioedema. When swelling persists for greater than a few days or is unresponsive to treatment for urticaria/angioedema, other etiologies should be considered. In most instances, a thorough history and physical examination will define other etiologies. However, for more persistent conditions, further laboratory evaluation and a biopsy may be required to define the diagnosis. Rarely is a more aggressive approach required to make the diagnosis. Clinicians should remember that if the swelling does not act like angioedema, it more than likely is not angioedema.