[Urticaria and angioedema].

Urticaria is a common complaint characterized by the eruption of cutaneous wheals, accompanied by redness and itching and in which mast cells are thought to play a central role. Wheals range from a few millimeters to several centimeters in diameter and are usually short lasting, except in case of urticarial vasculitis in which they last longer than 24 hours. Urticaria may occur alone or be associated with angioedema, that can be defined as a deep dermal and subcutaneous edema typically affecting the lips, face, hands, feet, penis or scrotum. Angioedema may also involve the submucosal tissue, and when the swellings occur in the oropharynx they can be alarming and occasionally life-threatening. In many cases the cause of acute urticaria or angioedema may be determined, whilst the pathogenetic and diagnostic aspects of the chronic forms are more complex and variable. The clinical features of, as well as the diagnostic and therapeutic approaches to the different forms of urticaria and angioedema are here reviewed, focusing on chronic idiopathic urticaria.