saudigastro.com/patients/autoimmune-pancreatitis
Category
Chronic
Red flags
5
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
What is it?
In autoimmune pancreatitis (AIP) the body's defence system mistakenly attacks the pancreas, causing swelling and scarring. There are two main types. Type 1 is part of IgG4-related disease, a condition in which a particular antibody-producing immune cell causes swelling in several organs, such as the bile ducts, salivary glands, kidneys or lymph nodes. Type 2 mainly affects the pancreas and is sometimes linked with inflammatory bowel disease. Because it can narrow the bile duct inside the pancreas, it often causes jaundice (yellowing) and a mass that looks like a tumour on scans, so careful assessment is essential.
How common is it?
It is a rare condition. Type 1 is seen more often in middle-aged and older men, and type 2 tends to affect younger people of both sexes. Because it is uncommon and can mimic pancreatic cancer, it is often found only after a specialist assessment.
Why does it happen?
The exact cause is not known. It is an immune-mediated condition: immune cells infiltrate the pancreas and cause swelling and fibrosis (scar tissue). It is not caused by alcohol or gallstones, and it is not infectious. Genetic and environmental factors may play a part, but nothing you did caused it.
Symptoms
- Painless yellowing of the skin and eyes (jaundice), dark urine and pale stools
- Mild upper abdominal discomfort or back pain, usually less severe than in other pancreatitis
- Weight loss and tiredness
- Loose, greasy stools if the pancreas makes fewer enzymes
- New or worsening diabetes
- Symptoms from other organs: swollen salivary or tear glands, dry mouth or eyes, kidney problems, or cough
Red flags — seek urgent medical care
Severe upper abdominal pain radiating to the back with vomiting
Possible acute pancreatitis or a complication. Go to the emergency room.
Jaundice with fever and chills
The blocked bile duct may be infected (cholangitis), a medical emergency. Go to the hospital immediately.
Any new yellow skin or eyes
Needs urgent assessment, because it can also be a sign of a tumour or gallstone blockage. Do not wait to see if it settles.
Extreme thirst, frequent urination, drowsiness or confusion
Possible dangerously high blood sugar, particularly if you take steroids. Seek emergency care.
Fever, cough or other signs of infection while on steroids or immune-suppressing medicine
Infections can be more serious on these drugs. Contact your doctor the same day.
How is it diagnosed?
Diagnosis needs a team approach because AIP can resemble pancreatic cancer. Doctors combine several clues: imaging (CT, MRI or endoscopic ultrasound) showing a swollen, sausage-like pancreas or a narrowed duct; blood tests including IgG4 levels (not always raised); evidence of other organ involvement; and, often, a tissue sample taken with a fine needle during endoscopic ultrasound to exclude cancer. Sometimes a short trial of steroids under specialist supervision is used when the picture is clear. Cancer must always be properly excluded first.
What the latest science says
International consensus criteria help doctors to diagnose AIP and tell the two types apart. Steroids remain first-line treatment, and for people whose disease returns, other immune-modifying medicines, including rituximab, are used in specialist centres. Ongoing research is looking at the best way to prevent relapses and the long-term risks of the disease.
Outlook — what to expect
Most people respond quickly to treatment, with jaundice and swelling improving over weeks. Type 1 disease can relapse, so follow-up is needed, sometimes with longer-term treatment. Type 2 relapses less often. Some people are left with reduced pancreatic function (needing enzymes) or diabetes. Regular follow-up helps to catch these early.
Treatment
Habits & Lifestyle
Daily habits cannot treat the disease but help you stay well on treatment.
- Take steroids exactly as prescribed and never stop them suddenly, since the body needs time to adjust.
- Do not drink alcohol and do not smoke, which can harm the pancreas.
- Keep all follow-up visits and scans, even when you feel well.
- Check your blood sugar if your doctor advises, particularly while on steroids.
- Tell your doctor about any signs of infection, and discuss vaccinations before starting immune-suppressing treatment.
Diet
There is no special diet for the disease itself, but diet helps manage the side effects of treatment and any pancreatic weakness.
- Eat a balanced diet with enough protein and calories; small frequent meals can help if appetite is poor.
- On steroids, limit sugary foods and drinks and reduce salt to help control blood sugar and fluid.
- Ask about calcium and vitamin D for bone protection during steroid treatment.
- If stools are greasy, tell your doctor; you may need enzyme replacement rather than a low-fat diet.
Medications
Treatment is decided and monitored by a specialist. Doses and length of treatment are individual and are never to be changed without advice.
- Corticosteroids (such as prednisolone) are the usual first treatment and are reduced slowly over weeks to months.
- Immune-modifying medicines (such as azathioprine) or rituximab may be used to prevent relapses.
- Your team may prescribe bone protection, stomach protection or diabetes medicine alongside steroids.
- Pancreatic enzyme capsules are given if digestion is affected.
- Report any side effects, including mood changes, poor sleep, high blood sugar, swelling or infection.
Procedures & Surgery
Procedures are used to confirm the diagnosis and to relieve blocked bile ducts.
- Endoscopic ultrasound with a needle sample helps to confirm the diagnosis and exclude cancer.
- A temporary stent (small plastic tube) placed through ERCP can open a blocked bile duct if jaundice is severe or there is infection.
- Surgery is avoided when the diagnosis is certain, but may be needed if cancer cannot be excluded.
Living with the condition
- Follow-up usually includes blood tests, scans and checks for relapse, diabetes and enzyme needs.
- Report any return of jaundice, pain or weight loss quickly.
- Carry a note listing your diagnosis and medicines, including steroids.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- Which type do I have, and could other organs be involved?
- Has cancer been properly excluded?
- How long will I take steroids and what side effects should I watch for?
- What is the chance of relapse, and what would we do?
- Do I need enzymes, or diabetes and bone checks?
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Status: Approved for publication by SGA; individual clinician review is ongoing · Published 24/04/2026
For general education only; it does not replace your doctor’s advice. Individual clinician review of this guide is ongoing. SGA clinician? Review this guide