Urticaria and autoimmunity: where are we now?

There is considerable debate whether chronic urticaria is an autoimmune disease or whether its features suggestive of autoimmunity are epiphenomena. A plethora of circumstantial evidence suggests that chronic urticaria is an autoimmune disease, but criteria to establish autoimmunity require direct proof and indirect evidence, and these are lacking in chronic urticaria. Current approaches to assessing for autoimmunity in vivo via the autologous serum skin test, and in vitro via either basophil histamine release or the basophil activation test are widely utilized, but the results of these tests have limited impact on prediction of the clinical course and efficacy of treatments. Recent guidelines for diagnosing autoimmune urticaria have been proposed, but further investigation is needed.