Differential Diagnosis for Elevated AST in a 14-Year-Old Girl
Single Most Likely Diagnosis
- Muscle injury or strenuous exercise: Elevated AST (aspartate aminotransferase) can be seen in conditions affecting the muscles, as AST is also present in muscle tissue. Given the age and the fact that the girl is otherwise healthy and of normal weight, recent muscle injury or strenuous physical activity could easily account for the mildly elevated AST level.
Other Likely Diagnoses
- Viral hepatitis: Although less common, viral hepatitis (such as hepatitis A, B, or C) can cause elevated liver enzymes, including AST. The diagnosis might be more likely if there were other symptoms or risk factors present.
- Fatty liver disease: While less common in normal-weight adolescents, non-alcoholic fatty liver disease (NAFLD) can still occur and should be considered, especially if there are other risk factors such as a family history of fatty liver disease or metabolic syndrome components.
- Medication-induced liver injury: Certain medications, including some over-the-counter drugs and supplements, can cause liver enzyme elevations. A thorough medication and supplement history is essential.
Do Not Miss Diagnoses
- Wilson's disease: An inherited disorder that leads to copper accumulation in the liver, brain, and other organs. It's crucial to diagnose early to prevent irreversible damage. Although rare, it's a condition that could be deadly if missed.
- Autoimmune hepatitis: A condition where the body's immune system attacks liver cells. Early diagnosis and treatment are critical to prevent liver failure.
- Alpha-1 antitrypsin deficiency: A genetic disorder that may cause liver disease and lung disease. Identifying this condition is vital for managing the disease and preventing complications.
Rare Diagnoses
- Glycogen storage diseases: A group of inherited disorders that result from defects in enzymes involved in glycogen synthesis or breakdown. Some types can lead to elevated liver enzymes.
- Mitochondrial disorders: Conditions that affect the mitochondria, which can lead to a variety of systemic symptoms, including elevated liver enzymes in some cases.
- Cystic fibrosis: Although primarily known for its respiratory and pancreatic manifestations, cystic fibrosis can also affect the liver, leading to elevated liver enzymes and other liver-related issues.