Background. Vitiligo is an acquired hypopigmentary disorder. The prevalence of vitiligo is 0.1–2% worldwide. Numerous autoimmune diseases are associated with vitiligo, including autoimmune thyroid diseases. The prevalence of thyroid abnormalities is up to 34% in vitiligo patients depending on ethnicities. Objective. This study aims to investigate thyroid abnormalities in Thai patients with vitiligo. Methods. Medical records of vitiligo patients attending outpatient dermatology clinic at a university-based hospital from 2012 to 2016 were retrospectively reviewed. Data regarding vitiligo, clinical features, and autoimmune thyroid laboratory results were retrieved and analyzed. Results. Among 325 vitiligo patients identified, anti-thyroid peroxidase and anti-thyroglobulin were positive in 90 (27.7%) and 63 patients (19.4%), respectively. Positive thyroid antibody was associated with female gender (p<0.001) and vitiliginous hand lesions (p<0.02). Out of 197 patients with complete thyroid function test, the prevalence of autoimmune thyroid diseases (AITD) is 12.7%. Female, nonsegmental type, higher affected area, and the presence of leukotrichia are significantly associated with AITD in vitiligo patients. Conclusions. Prevalence of positive thyroid antibodies and AITD in Thai patients with vitiligo is compatible with previous studies around the world. Screening for AITD with thyroid antibodies and serum TSH is essential for vitiligo patients.
Reactivity of anti-thyroid antibodies to thyroglobulin tryptic fragments: comparison of autoimmune and non-autoimmune thyroid diseases