[A child with generalized myasthenia gravis successfully treated with tacrolimus]

A 7-year-old girl was diagnosed with generalized myasthenia gravis and became steroid-dependent. Dose of prednisolone could not be reduced to < 2 mg/kg/day on alternate days, despite adverse effects. Thymectomy was avoided. Oral tacrolimus was initiated at 1.0 - 1.3 mg/kg/day. Ptosis and weakness of the lingual and pharyngeal muscles began to ameliorate 2 weeks later, and disappeared within 2 months. Serum titer of anti-acetylcholine receptor antibody also declined. During the subsequent two years, remission was maintained although prednisolone was reduced to half the original dose. No adverse effects of tacrolimus were noted. This case suggests the usefulness of tacrolimus in the treatment of childhood myasthenia gravis.