Corticosteroid-induced Cushingoid Appearance in Myasthenia Gravis

Objective Corticosteroids are the primary immunosuppressants used to treat myasthenia gravis (MG). Their side effects, including Cushingoid appearance, are well documented. However, the precise relationship between corticosteroid usage and Cushingoid appearance has not been fully explored. Methods This study investigated the frequency and severity of Cushingoid appearance and their relationships with corticosteroid use. In total, 1,321 consecutive patients with MG who were prednisolone users, enrolled in the Japanese MG registry study 2021, were examined, and the severity of Cushingoid appearance was evaluated using the Cushingoid appearance index. Results The rates of Cushingoid appearance at survey and peak were 36.4% and 62.0%, respectively. Multivariate regression analyses revealed that the current Cushingoid appearance index was correlated with the current prednisolone dose, duration of prednisolone dose >10 mg/day, and female sex. The risk of Cushingoid appearance was classified according to prednisolone dose and duration using a decision tree. The Cushingoid appearance index significantly decreased with decreases in the prednisolone dose during the 6 years of follow-up. The Cushingoid appearance index was also significantly correlated with the MG-Quality of Life 15-revised score. Conclusion This study elucidated the relationship between corticosteroid treatment and Cushingoid appearance in MG, suggesting that the high-dose and long-term use of corticosteroids should be avoided to improve the patient quality of life.