Tropical Chronic Pancreatitis

Tropical chronic pancreatitis is an idiopathic, early onset chronic pancreatitis with large intraductal calculi, found mainly in tropical regions such as southern India, Kerala and parts of Africa. It is also called fibrocalculous pancreatic diabetes when diabetes is present.

Onset is usually in childhood or young adulthood (mean age at diagnosis 20 to 30 years), the sexes are affected about equally, and the typical sequence is abdominal pain in childhood, then calculi, then diabetes and steatorrhoea. Pancreatic cancer risk is raised many fold compared with the general population.

Pathophysiology.

Proposed causes are genetic variants (SPINK1 and PRSS1 mutations are common), cyanogenic cassava toxicity, malnutrition and oxidative stress. Ductal protein plugs calcify to form large stones, which obstruct the duct, with fibrosis, atrophy and loss of exocrine and endocrine function.

Recurrent severe upper abdominal pain radiating to the back, steatorrhoea with weight loss, and diabetes that is insulin requiring but usually not ketosis prone. Wasting, vitamin deficiency and pain related disability are frequent.

Red flags.

• New or changed pain with weight loss (cancer).
• Jaundice or cholangitis.
• Pseudocyst or splenic vein thrombosis.
• Diabetic ketoacidosis or severe hypoglycaemia.

Plain abdominal radiograph, ultrasound or CT shows large calculi in a dilated main duct with parenchymal atrophy. Magnetic resonance cholangiopancreatography defines ductal anatomy. Faecal elastase under 200 micrograms/g confirms exocrine failure. Check glucose, HbA1c, calcium, vitamin D, B12 and fat soluble vitamins. Test CA 19-9 and obtain cross-sectional imaging if cancer is suspected.

Differential diagnosis.

• Alcohol related chronic pancreatitis.
• Hereditary pancreatitis.
• Pancreatic cancer.
• Type 1 or type 2 diabetes with exocrine insufficiency.
• Cystic fibrosis.

Start with analgesia, enzyme replacement, glycaemic control and nutrition. Remove or fragment large stones by extracorporeal shock wave lithotripsy with endoscopic clearance, and use surgical drainage (lateral pancreaticojejunostomy) for failed endoscopic treatment or dominant duct dilatation.

• Paracetamol: 1 g orally every 6 hours; maximum 4 g daily (3 g daily if weight under 50 kg, in chronic liver disease or with alcohol misuse); monitor liver tests; reduce dose in malnutrition.
• Tramadol (when paracetamol is insufficient): 50 to 100 mg orally every 6 hours; maximum 400 mg daily (300 mg daily over 75 years); monitor sedation and seizure risk; give every 12 hours when creatinine clearance is under 30 mL/min.
• Pancrelipase: 40,000 to 50,000 lipase units with each main meal and 20,000 to 25,000 with snacks; maximum 10,000 lipase units/kg daily; monitor stool, weight and fat soluble vitamins; reduce the dose if 10,000 units/kg daily is exceeded.
• Insulin (diabetes): start 0.3 units/kg daily subcutaneously as a basal and meal time regimen; titrate by 10% to 20% every 3 days; maximum 1 unit/kg daily before reassessing for resistance; monitor glucose, as glucagon deficiency makes hypoglycaemia more severe; reduce in renal impairment and in poor oral intake.

Give vitamin D, calcium and fat soluble vitamins when deficient.

Monitoring. Pain, weight and HbA1c every 3 months; yearly bone density, vitamin levels and eye and kidney screening; low threshold for cancer imaging.

Referral and escalation. Pancreatic endoscopy and surgery; diabetologist; dietitian.

Special groups. Children need weight based dosing and growth monitoring.