ABSTRACT
Acute urticaria is extremely common, possibly affecting as many as 10-20% of the population at some time in their lives. It is most frequently a self-limited disorder caused by an allergic reaction to a food or drug. When the urticaria exceeds 6 weeks, it is rather arbitrarily designated as chronic. Different types of classification have been suggested, depending on pathophysiology, aetiology and clinical features. The classification given in Table 4.1 is intended to provide a better understanding of urticaria with regard to its clinical evaluation and management.
