Dr. Pearl E. Grimes
Frontline Medical News, 2014 Aug 22, B Jancin
COEUR D’ALENE, IDAHO (FRONTLINE MEDICAL NEWS) – Every child and adolescent with vitiligo should undergo a laboratory evaluation that includes thyroid function tests and antibody levels, Dr. Pearl E. Grimes advised at the annual meeting of the Society for Pediatric Dermatology.
“At some point, we used to debate whether thyroid disease really is more common in the pediatric population with vitiligo. But now we have multiple studies in the literature to suggest that it is. And that certainly has also been my own clinical experience in looking at thyroid function tests as well as thyroid antibodies for the past 25 years in the pediatric population,” said Dr. Grimes, director of the Vitiligo and Pigmentation Institute of Southern California and a dermatologist at the University of California, Los Angeles.
Vitiligo is an autoimmune disease. As such, it is well known to be associated with other autoimmune diseases in adults, with Hashimoto’s thyroiditis and other forms of thyroid disease being the most common comorbid autoimmune conditions.
Dr. Grimes cited two recent studies showing a sharply increased prevalence of thyroid abnormalities as well in the pediatric population with vitiligo.
Investigators at the Netherlands Institute for Pigment Disorders in Amsterdam reported on 260 children and adolescents with vitiligo who underwent measurement of thyroid-stimulating hormone, free thyroxine, and antithyroid peroxidase antibody levels. The results indicated 6.2% had autoimmune thyroiditis with thyroid hormone disturbances, a prevalence far greater than that seen in the general pediatric population. Moreover, 10.5% of patients had elevated levels of antithyroid peroxidase antibodies without disturbance of thyroid hormone, a condition known to be associated with an increased risk of developing overt thyroid disease down the road (Horm. Res. Paediatr. 2013;79:137-44).
In another study, investigators at Children’s Hospital in Izmir, Turkey, retrospectively reviewed laboratory findings in 79 vitiligo patients, aged 2-15 years. Fully one-quarter had abnormal results on thyroid function tests and/or elevated thyroid autoantibodies (Indian J. Endocrinol. Metab. 2013;1096-9).
Dr. Grimes recommended that a routine laboratory screening panel for children and adolescents with vitiligo should “at a bare minimum” consist of a CBC with differential, a thyroid panel, thyroid antibodies, and an anti-nuclear antibody level.
“I’ve been looking at ANAs [antinuclear antibody test results] in children and adults with vitiligo for a very long time. I find that about 30% of patients, including kids, will have a positive ANA. What’s the significance? A small cohort of vitiligo patients will go on to develop lupus. Although lupus is not one of our more common autoimmune diseases, it happens. If the ANA titer is less than 1:160, I typically don’t get a lupus panel; but if it is greater than 1:160, I will follow up with a lupus panel – and that determines whether I will send that patient for a rheumatologic consultation. The ANA is also very important in determining whether a vitiligo patient is a candidate for phototherapy. If there’s a high-titer ANA, I will not place a patient on narrow band UVB (therapy),” according to Dr. Grimes.
She reported having performed clinical research for and serving as a consultant to several pharmaceutical and cosmetics companies.