Differential Diagnosis for Elevated Creatinine Kinase and ALT

Single Most Likely Diagnosis

• Muscle Injury or Rhabdomyolysis: This condition is characterized by muscle breakdown, leading to the release of creatinine kinase (CK) into the bloodstream. Elevated ALT can also occur due to muscle damage. The combination of these two findings often points towards muscle injury as the primary cause.

Other Likely Diagnoses

• Hepatitis: Although primarily associated with liver dysfunction, hepatitis can lead to elevated ALT levels. In some cases, especially if there's significant muscle involvement or secondary muscle injury, CK levels might also be elevated.
• Musculoskeletal Disorders: Conditions like muscular dystrophy can cause chronic elevation of CK due to ongoing muscle damage. ALT might be mildly elevated in some cases, possibly due to secondary effects on the liver or muscle-liver enzyme overlap.
• Intensive Exercise or Muscle Strain: Strenuous physical activity can lead to muscle damage, resulting in elevated CK levels. ALT might also be slightly elevated, although this is less common.

Do Not Miss Diagnoses

• Acute Liver Failure: Although less likely to present with significantly elevated CK, acute liver failure can lead to a range of enzyme abnormalities, including ALT elevation. CK might be elevated in the context of multi-organ failure or secondary muscle damage.
• Toxicity or Poisoning (e.g., Statin-Induced Myopathy): Certain medications, like statins, can cause myopathy, leading to elevated CK levels. ALT might also be elevated due to liver stress or damage from the toxin.
• Infections (e.g., Viral Myositis): Certain viral infections can cause myositis, leading to elevated CK. ALT might be elevated if the virus also affects the liver or if there's secondary liver involvement.

Rare Diagnoses

• Glycogen Storage Diseases: These are genetic disorders that affect the body's ability to store glycogen, leading to muscle and sometimes liver enzyme elevations.
• Mitochondrial Myopathies: A group of disorders that affect the mitochondria, leading to muscle weakness and enzyme elevations, including CK and potentially ALT.
• McArdle Disease (Glycogen Storage Disease Type V): A rare genetic disorder that affects muscle glycogen metabolism, leading to elevated CK levels after exercise. ALT might be mildly elevated in some cases.