Acute Pancreatitis Etiologies

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The classic, highest-yield mnemonic for recalling causes of acute pancreatitis, with gallstones and alcohol accounting for ~70% of presentations.

Acute pancreatitis represents sudden inflammation of the pancreas initiated by premature activation of zymogen granules (notably trypsinogen to trypsin), causing autodigestion. Recognizing the underlying trigger is vital for immediate therapy and recurrence prevention.

Systematic Breakdown

Idiopathic

10-20% of cases where initial laboratory, imaging, and history uncover no clear etiology (microlithiasis often found on EUS).

Gallstones

Most common cause (~40%). Stone transiently or permanently lodges in the ampulla of Vater, creating backward pressure or bile reflux into the pancreatic duct.

Ethanol (Alcohol)

Second most common cause (~30%). Chronic alcohol abuse promotes protein plug precipitation and sensitizes acinar cells to cholecystokinin.

Trauma

Blunt abdominal trauma (steering wheel or bicycle handlebar injuries compressing the pancreas against the lumbar spine), or operative trauma.

Steroids

Glucocorticoids can alter lipid metabolism and increase pancreatic secretion viscosity.

Mumps / Malignancy

Mumps virus, Coxsackievirus B, CMV, or pancreatic ductal adenocarcinoma obstructing outflow.

Autoimmune

Autoimmune pancreatitis (Type 1 IgG4-related systemic disease vs Type 2 isolated pancreatic disease).

Scorpion Venom

Tityus trinitatis scorpion sting (classic high-yield tropical board question causing massive acetylcholine discharge).

Hypercalcemia / Hypertriglyceridemia

Hypercalcemia stimulates trypsinogen activation; serum triglycerides > 1,000 mg/dL (11.3 mmol/L) liberate toxic free fatty acids.

ERCP

Post-ERCP pancreatitis occurs in 3-10% of diagnostic or therapeutic procedures due to mechanical or hydrostatic trauma.

Drugs

High-yield culprits: Azathioprine, 6-MP, Didanosine, Valproic acid, Thiazides, Furosemide, and Sulfonamides.

High-Yield Clinical Pearls & Exam Tips

Serum lipase rises within 4-8 hours, peaks at 24 hours, and remains elevated for 8-14 days with higher sensitivity and specificity than amylase.
Diagnosis requires at least 2 of 3: epigastric pain radiating to back, lipase/amylase > 3x upper limit of normal, or characteristic CT findings.
Normal lipase does NOT exclude late-presenting or hypertriglyceridemic pancreatitis (triglycerides interfere with assay).

Related Pharmaceuticals

Azathioprine Valproic Acid Didanosine Furosemide

Related Clinical Conditions

Cholelithiasis Hypertriglyceridemia Hyperparathyroidism

Authoritative Sources: First Aid for the USMLE Step 1 (2024) · Harrison's Principles of Internal Medicine 21e · ACG Clinical Guideline: Management of Acute Pancreatitis