Differential Diagnosis for Asymptomatic Rise in Total Bilirubin in the Context of Myositis

• Single Most Likely Diagnosis
  • Statins-induced myopathy and liver injury: Many patients with myositis are on statins for associated conditions like hyperlipidemia. Statins can cause an asymptomatic rise in liver enzymes, including bilirubin, due to their potential for hepatotoxicity and myopathy.
• Other Likely Diagnoses
  • Autoimmune hepatitis: This condition can present with elevated liver enzymes and bilirubin and is often associated with autoimmune diseases, including some forms of myositis.
  • Primary biliary cholangitis (PBC): Although more common in women, PBC can cause an asymptomatic elevation in bilirubin and is associated with various autoimmune diseases.
  • Drug-induced liver injury (DILI) from other medications: Besides statins, other drugs used in the treatment of myositis or its associated conditions can cause liver injury, leading to elevated bilirubin levels.
• Do Not Miss Diagnoses
  • Wilson's disease: A genetic disorder leading to copper accumulation in the liver, which can cause liver dysfunction and myopathy. Although rare, missing this diagnosis can be catastrophic due to the potential for severe liver damage and neurological deterioration.
  • Alpha-1 antitrypsin deficiency: This genetic disorder can cause liver disease and might be associated with myopathy, making it crucial not to miss, despite its lower likelihood.
• Rare Diagnoses
  • Gaucher's disease: A lysosomal storage disorder that can lead to liver dysfunction and muscle weakness, among other symptoms.
  • Danon disease: A rare X-linked dominant disorder characterized by cardiomyopathy, myopathy, and intellectual disability, with some cases presenting with liver dysfunction.