Graves’ disease (GD) is responsible for more than 90% of all cases of hyperthyroidism in children. Hyperthyroidism in GD is due to stimulating antibodies directed to TSH receptors, known as TRAb (Thyrotropin Receptor Antibody), that mimic the effects of TSH. Infrequent causes of hyperthyroidism include activating mutations of genes related to TSH receptors and G protein alpha subunit and inadequate secretion of TSH seen in pituitary TSH secreting tumors and thyroid hormone resistance syndrome (THRS) while thyrotoxicosis is seen in Hashimoto’s and subacute thyroiditis. Initial treatment of GD is done with antithyroid drugs (ATD) while definitive treatment is accomplished with either ATD, radioactive iodine (131I) or subtotal thyroidectomy. None of these alternatives is totally safe, effective and able to afford a permanent euthyroid state. beta-blockers can be used in all forms of hyperthyroidism to attenuate sympathetic signs. ATD inhibit T3 and T4 synthesis and show immunosuppressive effect. Propylthiouracil (PTU) reduces the T4 to T3 conversion. PTU, 5-10mg/kg/d, or methymazole, 0.5-1.0mg/kg, once a day, are commonly used. l-thyroxine, 100µg/m2/day should be added once the child is euthyroid. Remission rate is low. Mild adverse effects (rash, nausea, headache, and arthralgia) are not infrequent, whereas severe side effects (hepatitis, vasculitis, purpura fulminans and agranulocytosis) are fortunately rare. Recurrences can be treated with a new cycle of ATD, 131I or thyroidectomy. Mortality rate in thyroidectomy is low (0.08%) and the cure rate is around 80%. 131I is safe and cheap. It’s use as first choice therapy is increasing in different countries. High enough doses of 131I that lead to a complete ablation of the gland are advocated. Hypothyroidism should be adequately treated with l-thyroxine. Surgery and 131I are indicated to patients with TSH receptor and G protein alpha subunit gene mutations. Surgery also is the best treatment for pituitary TSH secreting tumors. In patients with THRS, T3 or triiodothyroacetic acid (TRIAC) have been used. Thyrotoxicosis due to follicular disruption is managed with beta-blockers.
Graves disease; TRAb; alpha subunit; G protein; Anti-thyroid drugs; 131I-Iodine