Acute Urticaria

This chapter discusses the background, diagnosis, treatment, and prognosis for acute urticaria. Urticaria is characterized by skin findings of spontaneously erupting, pruritic, short-lived wheals (or hives), which may be caused by a variety of triggers or may be idiopathic, and may be associated with angioedema. Acute urticaria refers specifically to urticaria that does not exceed 6 weeks in duration. The lesions of acute and chronic urticaria are identical, so when they first develop it is not possible to differentiate acute from chronic urticaria by physical examination. There are numerous possible causes of acute urticaria, and for many patients no specific etiology can be identified. In some cases, urticaria may be a presenting feature of a systemic disorder or may persist and represent the beginning of chronic urticaria. Non-sedating second generation H1 antihistamines are the mainstay of therapy for acute urticaria.