Differential Diagnosis for High AST compared to ALT plus Fever
- Single most likely diagnosis + Viral hepatitis: This is the most likely diagnosis because viral hepatitis, such as hepatitis A, B, or C, can cause elevated liver enzymes, with AST often being higher than ALT, especially in the acute phase. Fever is also a common symptom in acute viral hepatitis.
- Other Likely diagnoses + Alcoholic liver disease: Although ALT is typically higher than AST in alcoholic liver disease, in some cases, especially with advanced disease or when combined with other liver insults, AST can be higher. Fever can occur due to associated infections or other complications. + Medication-induced liver injury: Certain medications can cause liver damage, leading to elevated liver enzymes. The pattern of enzyme elevation can vary, and some medications may cause AST to be higher than ALT. Fever can be present if the reaction is severe or if there's an associated infection. + Ischemic hepatitis: This condition, also known as shock liver, occurs due to reduced blood flow to the liver and can result in significantly elevated AST and ALT, often with AST being higher. Fever might not be a primary symptom but can occur in the context of the underlying cause of ischemia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.) + Acute bacterial or fungal infections (e.g., abscesses, cholangitis): These conditions can cause fever and elevated liver enzymes. Although less common, they are critical to diagnose and treat promptly to prevent severe outcomes. + Malignancy (e.g., liver metastases, lymphoma): In some cases, malignancies can cause elevated liver enzymes and fever. Early detection is crucial for treatment and prognosis. + Autoimmune hepatitis: This condition can present with elevated liver enzymes and systemic symptoms like fever. It's essential to diagnose and treat autoimmune hepatitis to prevent liver damage.
- Rare diagnoses + Wilson's disease: A genetic disorder that leads to copper accumulation in the liver, causing liver damage. It can present with elevated liver enzymes, but the pattern can vary. Fever is not a typical primary symptom but can occur. + Alpha-1 antitrypsin deficiency: A genetic disorder that can cause liver disease and elevated liver enzymes. The enzyme pattern can vary, and fever might not be a primary symptom but can be present in the context of lung disease or other complications. + Budd-Chiari syndrome: A rare condition caused by thrombosis of the hepatic veins, leading to liver dysfunction. It can present with elevated liver enzymes and fever, among other symptoms.