Chronic Spontaneous Urticaria: The Role and Relevance of Autoreactivity, Autoimmunity, and Autoallergy.

Chronic spontaneous urticaria (CSU) is a frequent and often severely disabling disease. A large number of studies were performed during the last 2 decades to clarify its pathogenesis. These studies shed light on the underlying autoimmune mechanisms of CSU pathogenesis and have led us to understand that different mechanisms may exist and, sometimes, coexist behind the same clinical presentation. The present article reviews the meaning of the terms autoreactivity, autoimmunity, and autoallergy, which have been variably used over the years to define different endotypes of the disease. Furthermore, we discuss the methods potentially able to lead us to the correct classification of CSU patients.