Although acute urticaria is often caused by an allergy, chronic urticaria is now recognized as an autoimmune disease, usually caused by production of autoantibodies to IgE. Allergy tests are not indicated. Most patients will respond to antihistamines, although higher than usual doses may be required. For a recent review of the topic by Kolkhir et al in J Allergy Clin Immunol, 2022 click on DOI: 10.1016/j.jaci.2022.04.010.
