IMPE Abstracts

Introduction: The prevalence of vitiligo in the general population is 0.5 to 1%. Children under 12 years represent 23% of the patients with vitiligo. The most common type of vitiligo (85% of total) is the non-segmental. The prevalence of autoimmune thyroid disease in patients with non-segmental vitiligo is greater than the one reported in the general population. Hypothyroidism is the most common disorder seen in children with non-segmental vitiligo. Early diagnosis of thyroid dysfunction is important because thyroid hormones influence growth, puberty, bone growth, metabolism and physiological functions of children.

Objective: To determine the usefulness of screening for autoimmunity and thyroid dysfunction in children and adolescents with non-segmental vitiligo.

Material and methods: Patients younger than 15 years diagnosed with non-segmental vitiligo.

Variables: Age, sex and BMI of the patients. Anti-TPO antibodies concentrations (anti-TPO concentrations higher than 35 IU/mL were considered positive). Serum levels of TSH and FT4. Reference levels: FT4, 0.8-1.9 ng/dL; TSH, 0.4-4.0 ulU/mL. Hormone levels exceeding these established ranges were considered patological. The diagnosis of autoimmune thyroiditis was based on increased concentration of anti-TPO antibodies.

Results: Investigated universe: 29 patients with non-segmental vitiligo. Mean or age: 12.1 years (SD 0.9). Age range: 8-14 years. Sex: 18 (62%) female and 11 (38%) male. BMI: 17.9 (SD 0.8). Laboratory: * Negative anti-TPO, normal levels of TSH and FTA: 21 patients (72.5% of the cases). * Positive anti-TPO (range, 49-164 U/mL); normal levels of TSH and FT4: Six patients (20.7%). * Subclinical hypothyroidism (positive anti-TPO, 137 IU/mL; TSH 8.2 uIU/mL; FT4, 1.4 ng/dL): One patient (3.4%). * Overt hypothyroidism (positive anti-TPO, 129 IU/mL; TSH, 9.5 uIU/mL; FT4, 0.6 ng/dL): One patient (3.4%).

Conclusions: The frequency of autoimmune thyroid disease in patents with no-segmental vitiligo was elevated. The anti-TPO were positive in a quarter or patients. Hypothyroidism was the most common disorder seen in children and adolescents with non-segmental vitiligo.

Recommendation: Periodic evaluation of anti-TPO concentrations is recommended and thyroid hormone levels in children and adolescents with non-segmental vitiligo, to diagnose and treat at an early-stage thyroid dysfunction.