Special features of Graves' disease in early childhood.

Graves' disease (GD) is extremely rare in children younger than 4 years of age, but if not recognized and treated it can seriously interfere with growth and development. We report three unrelated children, all females, in whom GD occurred before the age of 3. These children presented with goiter, exophthalmos, tachycardia, and hyperactivity. Moreover, one showed a severe psychomotor delay, and had previously undergone surgery due to craniosynostosis; the other two manifested a language delay. All had high thyroid hormones and thyrotropin receptor antibody (TRAb) serum levels that clearly indicated autoimmune hyperthyroidism. In all of them, the disease presumably had developed during the first or second year of life. No maternal history of GD was present in two. The third child was born to a mother affected with GD during pregnancy, but it is likely that her GD began to develop after 6 months of life. These children are being treated with methimazole, and treatment is still necessary after 32 months. TRAb levels were persistently high at follow-up. Psychological evaluation including language development at follow-up was appropriate for age in two children; the third child improved, but severe mental retardation is still evident. GD assessment in early childhood also needs to focus on psychological evaluation. Pediatricians should be aware of the possibility of permanent brain damage and craniosynostosis due to hyperthyroidism in infancy.