Severe Anti-HMG-CoAR Necrotizing Autoimmune Myopathy Secondary to Statin Use

Immune-mediated necrotizing myopathy is an uncommon but debilitating disease that can be triggered by drugs, toxins, or cancer. It is similar to polymyositis in presentation but is differentiated by findings on muscle biopsy. We present a case of a 79-year-old male on statin therapy who presented with proximal muscle weakness and elevated creatinine kinase (CK) levels. He had a confirmatory muscle biopsy for immune-mediated necrotizing myopathy. Unfortunately, the patient's condition eventually escalated, involving respiratory and esophageal muscles in spite of prompt diagnosis and treatment.