Synopsis
Distinguish the two major autoimmune pancreatitis subtypes, complete a pancreatic-cancer assessment before considering steroids, and monitor a source-based induction regimen for response, toxicity and relapse.
- Type 1 autoimmune pancreatitis is the pancreatic manifestation of IgG4-related disease and can involve bile ducts, salivary glands, kidneys and other organs.
- Type 2 is a distinct duct-centred disorder with granulocytic epithelial lesions; inflammatory bowel disease is an association and serum IgG4 may be normal.
- Combine imaging, tissue, serology and other-organ assessment. Neither a raised IgG4 nor a small negative biopsy settles the diagnosis; complete the malignancy assessment before a steroid trial, whose response does not itself exclude cancer.
Key red flags
A focal pancreatic mass, progressive jaundice or unexplained weight loss without a completed diagnostic assessment.
Fever, rigors or deteriorating physiology with biliary obstruction.
New infection, severe psychological symptoms, visual change or inability to retain essential steroid treatment during therapy.
A focal mass, jaundice and weight loss can occur in either autoimmune disease or cancer. Mild IgG4 elevation and non-specific inflammatory cells are insufficient reassurance. Assess the whole imaging and pathological picture in the pancreatic multidisciplinary team; a discordant or inadequately sampled lesion may require repeat investigation before treatment is safe.
Investigation priorities
Assess the parenchymal and ductal pattern and evaluate a possible malignancy.
Management branches
A 50 kg adult develops jaundice and mild upper abdominal discomfort. Imaging shows diffuse pancreatic enlargement and bile-duct involvement without features of cholangitis.
- The pancreatic team reviews imaging, markedly elevated IgG4 and a representative core biopsy showing the characteristic type 1 pattern. The complete assessment is concordant and important malignant alternatives have been addressed; the absence of malignant cells is not used in isolation. After infection, glucose, bone and medicine review, the team prescribes Milpharm prednisolone 5 mg soluble tablets, six tablets (30 mg) orally each morning for a planned four-week induction, with written safety and taper instructions.
- At two weeks the jaundice and discomfort have improved, bilirubin has fallen from 108 to 34 micromol/L and repeat imaging shows reduced pancreatic and biliary inflammation. Glucose and blood pressure remain acceptable and there are no significant psychological or infectious adverse effects. The team continues the induction to the planned four-week review rather than stopping on the strength of early symptom relief.