Abstract Urticaria (hives) is a common disorder that may be associated with angioedema (swelling that occurs beneath the skin). It is generally classified as acute or chronic, and chronic urticaria is further classified as spontaneous or inducible Second-generation, non-sedating histamine type 1 (H1)-receptor antihistamines represent the mainstay of therapy for both acute and chronic urticaria. Second-line treatment for uncontrolled chronic urticaria includes omalizumab (a monoclonal anti-immunoglobulin E [IgE] antibody). In this article, we review the causes, diagnosis and management of urticaria (with or without angioedema).

Key take-home messages Urticaria is a common disorder characterized by recurrent, pruritic (itchy) lesions with pale centers (wheals) that usually subside within 48 h; it can be associated with angioedema. Mast cells are the primary effector cells in urticaria. Urticaria is classified as acute (lesions for < 6 weeks) or chronic (lesions for ≥ 6 weeks). Chronic urticaria can be further classified as spontaneous or inducible. The diagnosis of urticaria is based primarily on a thorough clinical history and physical exam; however, diagnostic tests may be helpful in some instances. Second-generation, non-sedating H1-receptor antihistamines are the mainstay of therapy for urticaria. Omalizumab and cyclosporine can be used for more severe, chronic cases. Referral to an allergy specialist or dermatologist should be considered in the following situations: failure of or difficulty tolerating first-line second-generation antihistamine treatments; need for specialized treatment; and the presence of severe symptoms and/or atypical features.