Graves' disease associated with myasthenia gravis: report of one case.

Exophthalmos occurs in more than half of the patients with childhood Graves' disease, while severe Graves' ophthalmopathy is uncommon in children. Myasthenia gravis is even more rare in association with Graves' disease. A 7-year-old girl is reported; she had ptosis for two years; this was treated irregularly, and she then developed exophthalmos, ophthalmoplegia and thyroid goiter. Her laboratory tests showed T3 496 ng/dl, T4 17.05 ug/dl, TSH < 0.1 uU/ml, fT4 > 4.2 ng/dl. Antithyroglobulin antibody was 1:25600 and antimicrosomal antibody was 1:102400. Myasthenia gravis was confirmed by a positive neostigmine test. Due to allergic reaction to propylthiouracil, she was treated with carbimazole and propranolol. Thereafter the thyrotoxicosis was was well controlled. The ocular-type myasthenia gravis remained stable with minimum medical treatment.