10 Major Causes of Acute Pancreatitis
Gallstones and alcohol consumption are the two most common causes of acute pancreatitis, accounting for approximately 70-80% of all cases, with the remaining cases attributed to various other etiologies. 1
Primary Causes
Gallstones: The leading cause of acute pancreatitis in most countries, responsible for 45-60% of cases. Gallstone migration leads to obstruction of the pancreatic duct, causing inflammation 1, 2
Alcohol abuse: The second most common cause overall (20-25% of cases), though incidence varies by region. In chronic pancreatitis, alcohol is the etiological factor in 60-70% of cases 1, 2
Drug-induced pancreatitis: Medications such as azathioprine/6-mercaptopurine (occurs in ~4% of treated patients), valproic acid, and others can trigger pancreatitis. Some cases occur shortly after initial use while others develop after years of use 1, 3
Hypertriglyceridemia: Severe elevations in serum triglycerides (particularly levels >1000 mg/dL) can precipitate acute pancreatitis. It's both a potential cause and consequence of pancreatic inflammation 1, 4
Post-ERCP (Endoscopic Retrograde Cholangiopancreatography): A procedural complication that can trigger acute pancreatitis, especially in high-risk patients 4, 5
Less Common Causes
Anatomical abnormalities: Including pancreas divisum and other pancreatic duct abnormalities that can obstruct normal pancreatic drainage 1, 2, 4
Autoimmune pancreatitis: An immune-mediated form of pancreatitis that may be associated with IgG4-related disease 1, 2
Hypercalcemia: Elevated calcium levels can activate pancreatic enzymes prematurely, leading to autodigestion and inflammation 1
Infectious causes: Viral infections (mumps, Coxsackie B4) can occasionally trigger pancreatitis 1
Trauma/Surgery: Direct injury to the pancreas or post-surgical complications, particularly after abdominal or cardiac procedures 1, 6
Clinical Pearls and Caveats
Despite thorough investigation, approximately 10-25% of cases remain classified as "idiopathic." However, guidelines recommend that no more than 20-25% of cases should be labeled as such 1
When evaluating suspected idiopathic pancreatitis, at least two good-quality ultrasound examinations should be performed, as gallstones are often missed on initial imaging 1
Drug-induced pancreatitis is often a diagnosis of exclusion after ruling out more common causes. The relationship is established through temporal association, exclusion of other causes, and sometimes recurrence upon rechallenge 3, 7
Hereditary/genetic causes should be considered in young patients with recurrent episodes and no obvious etiology 2, 4
Pancreatic tumors can occasionally present as acute pancreatitis and should be considered particularly in elderly patients with idiopathic pancreatitis 1
The identification of the underlying cause is crucial for appropriate management and prevention of recurrent attacks. For example, gallstone pancreatitis may require cholecystectomy, while alcoholic pancreatitis necessitates abstinence from alcohol to prevent recurrence 2, 5.