Juvenile thyrotoxicosis--a South Island, New Zealand experience with long-term outcome.

Aim: To assess our experience in the management of juvenile thyrotoxicosis.

Method: Retrospective review of thyroid clinic records of juvenile (<16 y) thyrotoxic (JT) patients treated at thyroid clinic between 1972 and 1999. Long-term (>8 y) treatment outcome was assessed.

Results: During the 28-year period, 34 JT patients were diagnosed and treated--30 girls and 4 boys, median age 13 years (5.6-15.9 y). Thirty-two children had Graves' disease and two had toxic nodular goitre. All patients were initially treated with carbimazole, and no major adverse reactions occurred. One Graves' disease child later developed severe ophthalmopathy. During long-term follow-up, 12 of the 32 Graves' patients remain in remission after antithyroid drug treatment alone, but 4 of these 12 patients are currently receiving thyroxine replacement. Fifteen patients were surgically treated (median age 16 y), and six patients received radioiodine therapy (median age 18 y) including one patient with post-thyroidectomy relapse. The two patients with toxic nodular goitre were treated by thyroidectomy.

Conclusion: Juvenile thyrotoxicosis is relatively rare and not always due to Graves' disease. More than a third of children with Graves' disease achieved long-term remission following antithyroid drug therapy, and remaining patients required definitive therapy.