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.