**3. Epidemiology**

An episode of urticaria can occur in 15–25% of individuals at some point in their lifetime. Approximately 40% of patients with urticaria have wheals associated with angioedema and 1–13% of patients present with isolated angioedema [3, 7]. Socioeconomic status, ethnicity and education do not have any clear influence on the prevalence of the disease [3].

At first all cases of urticaria are acute; 30% of them progress to become chronic [7]. Acute episodic form of urticaria commonly presents in infancy and childhood, particularly in atopic subjects [1, 8]. Chronic urticaria peaks in adulthood between 20 and 40 years of age affecting women two times more frequently than men [1, 3, 4]. About 0.5–1% of population has chronic spontaneous urticaria at a specific point in time [3].
