Vitiligo and autoimmune thyroid disorders

Background: Vitiligo isa commonly acquired pigmentary disorder, in which there is loss or destructionof melanocytes leading to depigmentation. The exact etiology is unknown; it isbelieved to be multifactorial with various theories believed to play a role,the important ones being the autoimmune hypothesis and the oxidative stresstheory. The association of vitiligo with other autoimmune disorders, especiallythyroid diseases, is known.

**Aims & Objectives:**To determine if a statistically significant correlation exists between vitiligoand autoimmune thyroid disorders.

Methods: A case-controlstudy was carried out on 64 vitiligo patients (41 females and 23 males) and 64age and sex-matched healthy volunteers. Patients with known thyroid disease,having history of thyroid surgery and those receiving thyroid medications andimmunosuppressants were not included in the study. Serum T3, T4and TSH levels along with anti-TPO antibodies were measured in all thesubjects.

Results: There were 13cases (20.3%) with thyroid abnormalities in the study group compared to 4 cases(6.25%) in the control group. This difference was statistically significant (p= 0.03). Also, anti-TPO positivity was seen in 12 cases (18.8%) in the studygroup, while it was present in only 3 cases in the control group (4.7%)resulting in a statistically significant difference (p = 0.025). However, TSHabnormalities between the 2 groups did not vary significantly. Also, nostatistical significance was found in thyroid abnormalities between thechildren of the 2 groups. Anti-TPO positivity did not vary with diseaseseverity and activity of vitiligo.

Conclusions: It isrecommended that screening of otherwise asymptomatic vitiligo adults should becarried out on an individual basis, based on factors such as positive familyhistory, female gender and age group of 20-40 years for a more productive andcost-effective outcome. Also, it might not be fruitful to screen vitiligochildren for thyroid function. Similar larger studies are required to establishacceptable guidelines on full scale regular screening of vitiligo patients forthyroid function, especially in resource-limited settings.