Evaluation of Thyroid Dysfunction in Children: Screening Approaches and Referral Triggers to Endocrinology.

Thyroid diseases are common endocrinological disorders in children. The aim of this study is to evaluate the rate of actual thyroid dysfunction among children referred to pediatric endocrinology due to abnormal thyroid function test (TFT) results. All of the 204 children who were referred to the pediatric endocrinology clinic following an initial evaluation at the pediatric clinic in a tertiary care center were included. Clinical characteristics and TFT results of the subjects at both visits were evaluated according to the diagnosis of thyroid dysfunction. TFTs were performed for screening purposes in 42.7% of the cases. After endocrinology evaluation, 49.5% were found not to have thyroid dysfunction. There was no difference in thyroid dysfunction when only free thyroxine (fT4) levels at the initial visit were assessed. Among those with low initial thyroid-stimulating hormone (TSH), 80% had no thyroid dysfunction, while 57.6% with high TSH had thyroid dysfunction. If TSH remained high at follow-up, the risk of thyroid dysfunction increased 19.4-fold. TSH alone is adequate for the screening of thyroid dysfunction in children. For patients with initially abnormal TSH levels, a repeat TSH and fT4 evaluation should be conducted after 4 to 12 weeks before referral to pediatric endocrinology.