Successful treatment of four types of chronic urticaria with anti-IgE omalizumab in the same patient

Urticaria is a skin disorder that is characterized by the appearance of wheals (hives), angioedema, or both. 1 Chronic urticaria (CU) is defined as wheals (with or without angioedema) that persists for 6 or more weeks, and is further classified into 2 subtypes: chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). 1 In most cases of CU, a trigger cannot be identified. These cases are defined as CSU. The term inducible urticaria is used when a specific trigger can be linked to the development of CU. Skin lesions in inducible urticaria result from mast cell activation and mediator release. The mechanisms by which specific stimuli activate skin mast cells are not fully understood.