Effect of Levothyroxine Treatment on Clinical Symptoms in Hypothyroid Patients with Chronic Urticaria and Thyroid Autoimmunity.

BACKGROUND Thyroid autoimmunity has been increasingly reported to be associated with chronic urticaria (CU), and the possible clinical benefit of thyroid hormone or anti-thyroid drugs in some CU patients with autoimmune thyroid disease has been studied. However, the effect of thyroid hormone or anti-thyroid drugs on clinical symptoms of CU remains unclear. OBJECTIVE We investigated the clinical response of urticaria to the treatment of thyroid dysfunction. METHODS Medical records of patients with CU evaluated for thyroid autoimmunity and thyroid function were collected and reviewed. RESULTS Of 184 patients with CU, 43 patients (23.4%) had thyroid autoantibodies and 26 patients (14.1%) had thyroid dysfunction. While none of the five patients with Graves' disease showed any improvement of urticaria after treatment with anti-thyroid drugs, two of the 10 patients with Hashimoto's thyroiditis showed improved urticaria after being treated with levothyroxine. CONCLUSION Although levothyroxine treatment was effective in a minority of patients with CU, there may be a causal relationship between CU and thyroid autoimmunity.