Most Common Causes of Pancreatitis
Gallstones and alcohol are the two most common causes of pancreatitis, with gallstones accounting for 45-75% of cases and alcohol responsible for 20-25% of acute pancreatitis cases and 60-70% of chronic pancreatitis cases. 1, 2
Primary Etiologies
Gallstones: Leading cause of acute pancreatitis in most countries (45-75% of cases), with gallstone migration causing obstruction of the pancreatic duct and resulting inflammation 1, 2
Alcohol consumption: Second most common cause overall (20-25% of acute cases), though regional variations exist; alcohol is the predominant etiological factor in chronic pancreatitis (60-70% of cases) 1, 2
Drug-induced pancreatitis: Accounts for a significant portion of non-gallstone, non-alcoholic pancreatitis cases, with medications such as:
Less Common Causes
Hypertriglyceridemia: Severe elevations in serum triglycerides can both cause and result from pancreatic inflammation 2
Anatomical abnormalities: Including pancreas divisum and other pancreatic duct abnormalities that obstruct normal pancreatic drainage 1, 2
Autoimmune pancreatitis: Immune-mediated form that may be associated with IgG4-related disease 1, 2
Hypercalcemia: Can activate pancreatic enzymes prematurely, leading to autodigestion and inflammation 2
Infectious causes: Viral infections can occasionally trigger pancreatitis 2
Trauma or surgery: Particularly after abdominal or cardiac procedures 2
Idiopathic Pancreatitis
Approximately 10-25% of acute pancreatitis cases remain classified as "idiopathic," though guidelines recommend that no more than 20-25% of cases should be labeled as such 2, 5
The diagnosis of idiopathic pancreatitis should not be accepted without a thorough investigation for gallstones, which requires at least two good-quality ultrasound examinations 5, 2
Diagnostic Pearls and Caveats
When evaluating suspected idiopathic pancreatitis, advanced imaging techniques such as endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography (MRCP) may be necessary to detect microlithiasis, ductal anomalies, or pancreas divisum 5
EUS is as accurate and safer than ERCP for detecting common bile duct stones and should be used to identify patients who require therapeutic ERCP 5
Pancreatic tumors can occasionally present as acute pancreatitis and should be considered particularly in elderly patients with idiopathic pancreatitis 2
Fasting blood lipids and calcium concentrations should be determined in cases where the etiology is not immediately apparent 5
In the United States specifically, gallstones and excessive alcohol consumption remain the two most common etiologies of acute pancreatitis 6, 7, 8
Early laparoscopic cholecystectomy is indicated for patients with mild gallstone pancreatitis to prevent recurrence, as 20-30% of patients without cholecystectomy are readmitted within 90 days with biliary conditions or acute pancreatitis 8