Necrotizing autoimmune myositis following coronavirus disease 2019 infection: a case report

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 may be associated with late-onset necrotizing myositis, mimicking autoimmune inflammatory myositis; however, the exact underlying pathogenesis of severe acute respiratory syndrome coronavirus 2-induced myositis is still unclear. CASE PRESENTATION: Herein, we report a rare case of necrotizing autoimmune myositis in a 67-year-old middle eastern male following coronavirus disease 2019 infection, who presented with muscle weakness. The patient had positive anti-NXP2. The diagnosis of necrotizing autoimmune myositis was made according to muscle weakness, increased liver enzymes, electromyography and nerve conduction velocity results, and muscle biopsy. The patient underwent a full malignancy evaluation, which was unremarkable, and was discharged in relatively well condition with a daily dose of 1 mg/kg prednisolone and azathioprine 150 mg (2 mg/kg). CONCLUSION: Our report highlights the already known possible protracted sequence of coronavirus disease 2019 infection and the potential for delayed-onset necrotizing myositis.