Long-term outcome of thyrotoxicosis in childhood and adolescence in the west of Scotland: the case for long-term antithyroid treatment and the importance of initial counselling

Background Thyrotoxicosis is both rarer and more severe in children than in adults, rendering management difficult and often unsatisfactory. Objective To ascertain outcome in a geographically defined area of Scotland between 1989 and 2014. Method Retrospective case note review with follow-up questionnaire to family doctors for patients with Graves' disease and Hashimoto's thyroiditis. Results Sixty-six patients (58 females:8 males) comprising 53 with Graves' disease and 13 with Hashimoto's thyroiditis were diagnosed at median 10.4 (2.9-15.8) years and followed up for 11.8 (2.6-30.2) years. Antithyroid drug (ATD) therapy was stopped electively in 35 patients after 4.5 (1.5-8.6) years, resulting in remission in 10/13 Hashimoto's thyroiditis and 10/22 Graves' disease. Side effects occurred in 12 patients receiving carbimazole, six of whom changed to propylthiouracil; no adverse events occurred in the latter patients. Second-line therapy was given to 37 patients (34 with Graves' disease), comprising radioiodine (22) at 15.6 (9.3-24.4) years for relapse (6), poor control/adherence (14) or electively (2); and surgery (16) at 12 (6.4-21.3) years for relapse (4), poor control/adherence (5) and electively (7). Adherence problems with thyroxine replacement were reported in 10/33 patients in adulthood. Conclusions Hashimoto's thyroiditis should be distinguished from Graves' disease at diagnosis since the prognosis for remission is better. Remission rates for Graves' disease are low (10/53 patients), time to remission variable and adherence with both ATD and thyroxine replacement often problematic. We recommend (a) the giving of long term ATD rather than a fixed course of treatment in GD and (b) meticulous and realistic counselling of families from the time of diagnosis onwards.