Urticaria is a common condition – it is estimated that lifetime incidence of urticaria is approximately 15%, with females being affected more often than males. Both children and adults may develop urticaria, with the peak age of onset in adults being between 20 and 40 years. These guidelines outline recommendations for evaluating and managing urticaria. Urticaria consists of blancheable, erythematous, oedematous papules.
These papules vary in size from 1 mm to many centimetres –‘giant urticaria’, and are usually intensely itchy. They are caused by vasoactive mediators, predominantly histamine, released from mast cells. In the vast majority of cases they are transient, lasting for only a few hours in any one place, but with new weals appearing in other places. Etiology Despite thorough evaluation many cases remain unexplained (‘idiopathic’) but it may be possible to assign a specific…
