Autoimmune thyroiditis in children and adolescents: clinical and laboratory findings in 34 patients

Abstract

Autoimmune thyroiditis (AT) is the most common cause of nonendemic thyromegaly and acquired hypothyroidism in childhood and adolescence. Outgoing from an increasing number of newly diagnosed patients during the last years we performed a retrospective analysis including 34 patients treated between 1989 and 1998. Clinical data, laboratory and sonographical findings are described. Cases were ascertained by palpable thyroid enlargement or clinical signs of thyroid dysfunction and positive autoantibodies against thyroid tissue. Frequency of AT diagnosis has threefold increased since 1995 in our department. Age at diagnosis was 5.4 to 16.3 years (median 11.3). Palpable thyromegaly was present in 29 (85%) of our patients. Three patients had myxedema without goiter. Symptoms had been present for a period between 6 weeks and 7.5 years: median in all patients 6 months, median in hypothyroid patients 9 months. At time of diagnosis 15 patients suffered from hypothyroidism, 3 from hyperthyroidism and 7 patients showed normal levels of thyroid hormones. In 9 patients we found an isolated elevation of thyrotropin. 12 patients were prepubertal (Tanner I), 15 patients were pubertal (Tanner II-IV). 5 patients showed a dissociation of pubertal maturation. Ultrasound of thyroid gland showed an inhomogeneous and hypoechoic pattern in 32 patients. 30 patients were treated with thyroxine. Patients with persistent hyperthyroidism were treated with carbimazol. During the follow-up period enlargement of the thyroid gland decreased in one third of the patients. Thyromegaly caused by autoimmune thyroiditis gets an increasing importance. The high degree of obviously hypothyroid patients at the time of diagnosis reflects a delay of diagnosis. Early recognition and treatment of the disease should be achieved for a preventive care of hypothyroidism.