Prevalence of thyroid antibodies in Thai patients with chronic idiopathic urticaria.

One hundred Thai patients with chronic idiopathic urticaria (CIU) were studied to determine the prevalence of thyroid antibodies in comparison to 100 age- and sex-matched healthy volunteers. It was found that 21 patients (21%) with CIU were positive for thyroid antibodies. Among normal volunteers, only nine cases (9%) had elevated titers of thyroid antibodies. The frequency of thyroid antibodies in the chronic urticaria group was significantly more common than the control group (chi-square = 4.75, p=0.03). Among 21 patients with CIU who were positive for thyroid antibodies, 9 cases were negative for thyroid antibodies when repeating the tests after 3 months. Only 12 patients still had persistent elevation of antibodies after 3 months and thyroid function test was performed in these 12 patients. It was found that 9 cases had autoimmune thyroiditis with euthyroidism. One case had subclinical hyperthyroidism. One case had autoimmune hyperthyroidism, One case had subclinical hypothyroidism.