Synopsis
Distinguish autoimmune pancreatitis from pancreatic and biliary malignancy, recognise its systemic phenotypes, and use specialist-led immunosuppression while monitoring relapse, diabetes, obstruction and exocrine failure.
- Autoimmune pancreatitis is a fibro-inflammatory pancreatic disorder: type 1 usually belongs to IgG4-related disease, whereas type 2 is not typically IgG4-driven and is associated with inflammatory bowel disease.
- Painless obstructive jaundice, diffuse or focal pancreatic enlargement and duct narrowing can closely imitate pancreatic adenocarcinoma; diagnostic confidence must come from converging evidence.
- A raised serum IgG4 supports type 1 disease but lacks adequate specificity to exclude cancer, and a normal result does not rule out type 2 autoimmune pancreatitis.
Key red flags
Fever, rigors, hypotension or confusion with jaundice indicates possible infected biliary obstruction and requires emergency antibiotics plus source-control planning.
Investigation priorities
Define pancreatic morphology, duct strictures, biliary obstruction, vascular involvement and distant abnormalities.
Management branches
Imaging suggests autoimmune pancreatitis but pancreatic or biliary cancer remains possible.
- Stabilise cholangitis, organ failure or severe obstruction first, using urgent biliary expertise when source control is needed.
- Acquire pancreatic-protocol imaging and review prior scans for evolution, duct configuration, metastases and other-organ manifestations.
Key medicines
PrednisoloneUse a specialist-defined oral induction dose followed by a structured taper based on objective response and relapse risk.
RituximabAdminister only through a specialist IgG4-related disease protocol with commissioned indication, screening and infusion supervision.