A Case of Suspected Statin-Related Delayed Onset Necrotizing Myositis

Statin-induced necrotizing myositis is a rare subtype of idiopathic inflammatory myopathies due to the production of an antibody to the 200/100 kDA protein complex which was subsequently found to be directed against 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Similar to other auto-immune necrotizing myopathies, the disease is characterized by proximal muscle weakness, significant serum creatine kinase elevations, and histological evidence of necrosis of myocytes. However, there is often little to no infiltration of inflammatory cells noted on muscle biopsy. As the name implies, this subtype of idiopathic inflammatory myopathy is provoked by statin use which may be a helpful finding during the history-taking process when developing a differential diagnosis. Below, we discuss a case of a 52-year-old female with delayed-onset immune-mediated necrotizing myopathy secondary to statin use.