Muscle weakness in a girl with autoimmune hepatitis and Graves' disease.

Autoimmune hepatitis (AIH) is a chronic hepatic autoimmune disease of unknown etiology associated with inflammatory changes and autoantibodies. The combination of AIH, Grave's disease, and myasthenia gravis (MG) is rare, with only one other case reported. We report a pediatric patient with AIH type 2 and Grave's disease who developed MG whilst on a treatment with corticosteroids. A 13-year-old girl, diagnosed with thyrotoxicosis, was identified as having AIH type 2. During the course of her therapy, she developed muscle weakness. Investigations revealed increased anti-acetylcholine receptor (AChR) antibodies and her electromyography (EMG) was characteristic for MG. Her course is described here. This case highlights the importance of investigating muscle weakness in severely ill hospitalized patients.