Chronic Idiopathic Urticaria

Definition: In simple terms, this means hives that last a long time, for no known reason. In more specific medical terms, it means a form of hives (red patches on the skin), with or without angioedema, that last more than 6 weeks and have no known cause. Most cases of chronic idiopathic urticaria are caused by an autoimmune condition in which the body produces antibodies against its own allergic cells (mast cells and basophils), causing the release of histamine into the skin, leading to hives.