- Autoimmune disorder causing cholestasis, intra and extra hepatic biliary duct inflammation and stenosis
- 70-90% have IBD (typically ulcerative colitis)
- Avg age onset 40s
- 50% identified when no sx, on basis of lab abnormalities
- Progresses over 10-20 y to cirrhosis and end stage liver disease
- Increased risk for cholangiocarcinoma, gall bladder cancer, and colon cancer (risk higher than UC alone)
- Acute fever and pain if infection develops proximal to a stricture (e.g. post ERCP)
- Sometimes hepatomegaly, splenomegaly, jaundice, ascites (later findings)
- Elevated alkaline phosphatase (typically pre-dates symptoms)
- MRCP very helpful