Increased prevalence of thyroid dysfunction and diabetes mellitus in Indian vitiligo patients: A case-control study

BACKGROUND: Though it is well-known that vitiligo is associated with other autoimmune disorders, few Indian studies have focused on the relation between vitiligo, autoimmune thyroid dysfunction and diabetes mellitus. MATERIALS AND METHODS: This case-control study included 150 new cases of vitiligo and 100 age and sex-matched controls. A complete history and thorough dermatological examination was done. Serum samples from both patients and controls were collected and assayed for triiodothyronine, thyroxine, thyroid-stimulating hormone, anti-thyroid antibodies—anti-thyroid peroxidase and anti-thyroglobulin and fasting plasma glucose. RESULTS: Thyroid hormonal profile revealed autoimmune thyroid dysfunction manifesting as hypothyroidism in 30 (20%) vitiligo patients and two controls (2%). Diabetes mellitus was present in 24 (16%) vitiligo patients and five controls. Seven (4.7%) patients had both hypothyroidism and diabetes mellitus. CONCLUSION: There is a clear association between vitiligo, autoimmune hypothyroidism and diabetes mellitus. It would be very useful to screen for thyroid dysfunction and diabetes mellitus in all patients with vitiligo.