Resolution of chronic urticaria and angioedema with thyroxine.

Chronic urticaria (CU) is a clinically perplexing condition that not only can compromise the patient's quality of life but also frequently fails to respond satisfactorily to treatment with antiallergy medications such as antihistamines. For a considerable time, CU has been considered a disease of unknown etiology, but in recent years, a wide variety of causes and mechanisms have been suggested. An autoimmune basis linking the role of autoantibodies to thyroid tissue(s) in the pathogenesis of CU has been reported in a limited number of patients with the condition. Once diagnosed, most such cases respond well to the addition of thyroxine to the therapeutic regimen. Nevertheless, the evaluation of CU rarely includes consideration of the causal relationship of autoimmune thyroiditis in CU and inclusion of thyroid autoantibodies in the diagnostic regimen. This case report documents the dramatic improvement of a patient with CU after initiation of thyroxine therapy.