Rituximab for a rare pediatric case of concurrent thyroid eye disease and myasthenia gravis.

Rituximab (RTX) is a humanized chimeric anti-CD20 monoclonal antibody that leads to immunosuppression through rapid depletion of B lymphocytes. It has been demonstrated to be useful in treating both thyroid eye disease (TED) and myasthenia gravis (MG), respectively. However, the effectiveness of RTX in concurrent TED and MG cases is unclear and not previously reported in the literature. In this study, we describe a 13-year-old girl who presented with a 10-year history of general MG and a 1-year history of Graves' disease, bilateral proptosis, eye motility restriction, and lagophthalmos. A comprehensive evaluation confirmed the diagnosis of concurrent TED and MG. Satisfactory effectiveness was observed after RTX treatment without side effects. Based on the described observations, we suggest that RTX should be further explored as a treatment option for patients with concurrent TED and MG.