What is the most common (MC) risk factor for acute pancreatitis?

Most Common Risk Factor for Acute Pancreatitis

Gallstones are the most common risk factor for acute pancreatitis, accounting for approximately 50% of all cases. 1, 2

Etiology of Acute Pancreatitis

• Gallstone disease represents approximately half of all acute pancreatitis cases, making it the leading cause 2, 1
• Alcohol abuse is the second most common cause, accounting for 20-25% of cases 2, 3
• The remaining cases are attributed to various other causes or labeled as "idiopathic" when no obvious cause is identified 2, 3

Diagnostic Approach for Identifying Etiology

Initial Evaluation

• Thorough history should focus on previous gallstones, alcohol intake, family history, drug intake, and exposure to viral causes 2
• Initial laboratory tests should include pancreatic enzymes in plasma and liver function tests 2
• Ultrasound of the gallbladder should be performed to identify gallstones 2

Follow-up Investigations

• In the absence of identified gallstones or significant alcohol history, additional testing should include:
  • Fasting plasma lipids and calcium levels 2
  • Serum triglyceride levels over 11.3 mmol/l (1000 mg/dl) indicate hypertriglyceridemia as the etiology 2
  • Repeat biliary ultrasound, as the most sensitive test for diagnosis of gallstones that may have been missed remains a further ultrasound examination 2

Management Implications Based on Etiology

• For gallstone pancreatitis:

  • Urgent ERCP and sphincterotomy may be beneficial in severe cases, particularly with biliary obstruction or cholangitis 2, 1
  • Cholecystectomy should be performed within 2-4 weeks for mild cases to prevent recurrence 2, 1

• For alcohol-induced pancreatitis:

  • Moderation in alcohol consumption and avoiding alcohol abuse is recommended to prevent recurrence 3

Clinical Pearls and Pitfalls

• The diagnosis of idiopathic pancreatitis should not be accepted without a vigorous search for gallstones, including at least two good quality ultrasound examinations 2
• In recurrent cases with no identified cause, endoscopic ultrasound (EUS) may detect microlithiasis in the gallbladder or common bile duct 2
• MRCP has a sensitivity of 97.98% and specificity of 84.4% for choledocholithiasis and should be used when ultrasound does not show gallstones but clinical suspicion remains high 2
• Failure to identify and treat the underlying cause increases the risk of recurrent attacks and potential progression to chronic pancreatitis 4, 5