Can Influenza Cause Biliary Obstruction?
No, influenza does not directly cause biliary obstruction, but it can cause hepatic decompensation in patients with pre-existing cirrhosis, which is fundamentally different from mechanical biliary obstruction.
Direct Evidence on Influenza and Biliary Effects
The only documented relationship between influenza and biliary pathology involves hepatic decompensation in cirrhotic patients, not biliary obstruction. A case series demonstrated that influenza A infection caused hepatic decompensation requiring hospitalization in three patients with end-stage liver disease, manifesting as ascites, hepatic encephalopathy, and elevated aminotransferases—but not biliary obstruction 1.
Distinction Between Hepatic Decompensation and Biliary Obstruction
These are fundamentally different pathophysiologic processes:
- Hepatic decompensation from influenza presents with liver failure symptoms (encephalopathy, ascites, coagulopathy) in cirrhotic patients, with all patients recovering to baseline liver function within one month 1
- Biliary obstruction presents with conjugated hyperbilirubinemia, dilated bile ducts on imaging, and requires mechanical relief 2
Actual Causes of Biliary Obstruction
When evaluating biliary obstruction, the differential diagnosis includes 2:
- Malignant causes: Cholangiocarcinoma, pancreatic cancer, gallbladder cancer, lymphoma
- Benign causes: Choledocholithiasis, primary sclerosing cholangitis, strictures, parasitic infections
- Infectious cholangitis: Results from bacterial colonization of obstructed bile (not viral), with organisms like E. coli, Klebsiella, and enterococci 2, 3, 4
Critical Clinical Pitfall
Do not attribute biliary obstruction to influenza infection. If a patient with influenza presents with jaundice and elevated bilirubin:
- In cirrhotic patients: Consider hepatic decompensation from the viral infection itself 1
- In non-cirrhotic patients: Pursue standard workup for biliary obstruction with ultrasound as first-line imaging to identify mechanical causes 2
- Bacterial cholangitis requires biliary obstruction as a prerequisite—the infection is secondary to stasis, not a primary viral process 2, 3, 4
Rare Exception: Secondary Bacterial Infection
One case report documented Haemophilus influenzae (the bacterium, not influenza virus) causing biliary sepsis after percutaneous liver biopsy in a patient with pre-existing biliary obstruction from pancreatic tumor 5. This represents bacterial superinfection of an already obstructed biliary system, not viral causation of obstruction.