Check Thyroid Function in Children With Vitiligo
By: MICHELE G. SULLIVAN
ROME — Children with vitiligo should be regularly screened for thyroid dysfunction, as they may be at an increased risk for autoimmune thyroid disease, Talia Kakourou, M.D., reported in a poster session at the 10th World Congress of Pediatric Dermatology.
An increased prevalence of autoimmune thyroiditis is well documented in adults with vitiligo, she said, but the link has not been established in children. However, her study of pediatric vitiligo patients showed that autoimmune thyroid disease was 2.5 times more prevalent in that group than it was in age-matched controls who had sufficient iodine intake.
Dr. Kakourou administered thyroid function tests and thyroid ultrasound to 54 vitiligo patients aged 6–16 years. The criteria for autoimmune thyroiditis were a positive serum anti-thyroid-peroxidase (anti-TPO) and/or antithyroglobulin (anti-Tg) screen, and diffuse or irregular hypoechogenicity of the thyroid gland.
The mean age at onset of vitiligo was 7.7 years; disease duration was 1–16 years. Four of the patients had Hashimotos thyroiditis at the study outset and were already on T4 replacement therapy.
Tests demonstrated subclinical hypothyroidism in nine patients whose TSH levels were 4.5–8.5 mIU/mL. Eleven children (all nine of those with subclinical hypothyroidism, plus two additional children) had increased antithyroid antibodies, with anti-TPO levels of 50–75 IU/mL and anti-Tg levels of 10–84 IU/mL. Of these 11 children, 9 also showed hypoechogenicity of the thyroid gland. Therefore, Dr. Kakourou said, 13 of 54 (24%) fulfilled the criteria for autoimmune thyroiditis. The rate of autoimmune thyroiditis for school-aged children in Greece is 9.6%.
There were no statistically significant associations between thyroiditis and the children’s age, age at onset of disease, type of vitiligo, or family history of autoimmune disorders, she noted.
“We propose that children and adolescents with vitiligo should be annually screened for thyroid dysfunction, particularly autoimmune thyroiditis, in order to achieve early diagnosis and management of subclinical disease,” said Dr. Kakourou of Athens (Greece) University.