“Chronic idiopathic urticaria” is the medical term for hives that appear on the skin for no readily identifiable reason. When these itching, burning, painful skin rashes appear daily over prolonged periods, it can lead sufferers to become demoralized. While most cases of “acute urticaria” lasting less than six weeks seemed to be triggered by an allergic reaction, longer-lasting chronic idiopathic urticaria is seldom due to an allergy. In approximately one-third of cases, an autoimmune reaction may underlie the condition. In the absence of any identifiable cause to treat, chronic hive sufferers should avoid harsh soaps as well as any known triggers. In the meantime, the dermatologist can prescribe a number of medications, ranging from antihistamines to anti-inflammation drugs. Some chronic urticaria sufferers have other signs of autoimmune problems. Some have autoimmune thyroid disease, vitiligo, swollen joints, or certain abnormalities in the blood. Research shows that the injectable drug omalizumab (Xolair) is very effective against difficult-to-treat chronic hives without side effects.