Dermatomyositis, Rhabdomyolysis, and Statin-Induced Myopathy: A Case Report Illustrating the Spectrum of Myopathy

Abstract

This report describes a rare presentation of rhabdomyolysis and dermatomyositis in a patient with existing statin-induced myopathy, presenting with acute-on-chronic kidney disease. The patient had an initial diagnosis of statin-induced myopathy through mild creatinine kinase elevation following the prescription of atorvastatin. However, eight months after this, she presented with fulminant rhabdomyolysis following the introduction of furosemide and omeprazole. Dermatomyositis was diagnosed concurrently through a clinical presentation of heliotrope rash and proximal muscle weakness, which was confirmed by muscle biopsy. As the patient was already in advanced kidney failure with features of fluid overload, aggressive treatment with intravenous fluids was withheld. After failing to respond to high-dose steroids, the patient was treated early with intravenous immunoglobulins, which resulted in a rapid drop in creatine kinase level, improvement of muscle weakness, and renal function. This study depicts the nuanced and idiosyncratic spectrum of myopathy through a progressive transition of symptoms over a defined timeframe. It also highlights the adverse interactions between proton pump inhibitors, diuretics, and statins in triggering rhabdomyolysis and unmasking the presentation of dermatomyositis. Furthermore, it demonstrates the therapeutic effects of early intervention with intravenous immunoglobulin as rescue therapy for rhabdomyolysis in a situation where conventional fluid resuscitation was limited by advanced kidney failure.

Keywords: dermatomyositis; furosemide-induced rhabdomyolysis; idiopathic inflammatory myopathies; intravenous immunoglobulin therapy; proton pump inhibitor induced; rhabdomyolysis causing acute kidney injury; statin-induced rhabdomyolysis.

Figure 1. Heliotrope rash around eyes.

Figure 2. Trend of CK level against time with specific key events.

CK: creatine kinase