What are the causes and management of pancreatitis?

Causes of Acute Pancreatitis

Gallstones and alcohol abuse together account for approximately 75% of all acute pancreatitis cases, with gallstones being the single most common etiology (45-60% of cases) followed by alcohol (20-25% of cases). 1, 2

Major Etiologies

Gallstone Pancreatitis (Most Common)

• Gallstones are the leading cause overall, responsible for 45-60% of acute pancreatitis cases. 2 Migration of gallstones leads to obstruction of the pancreatic duct, triggering inflammatory cascade. 2
• Early elevation in serum aminotransferases or bilirubin strongly suggests gallstone etiology and should be assessed immediately. 1
• Transabdominal ultrasound should be performed early to detect gallstones, and repeated if initially negative, as gallstones are frequently missed on first imaging. 1, 2
• Most cases resolve within a few days with supportive management. 3

Alcohol-Induced Pancreatitis (Second Most Common)

• Excessive alcohol consumption accounts for 20-25% of acute pancreatitis cases, though regional variation exists. 2
• Document alcohol intake in units per week to accurately identify this etiology—incomplete alcohol history is a common pitfall that misses a major cause. 1
• Alcohol is the etiological factor in 60-70% of chronic pancreatitis cases, and repeated injury increases risk of progression from acute to chronic disease. 2, 4
• The incidence is increasing among younger populations due to rising alcohol consumption. 5, 2

Secondary Etiologies (Remaining 25% of Cases)

Post-ERCP Pancreatitis

• Endoscopic retrograde cholangiopancreatography can induce pancreatitis in 3-5% of procedures. 1
• This represents a high-risk subset with worse outcomes. 2

Drug-Induced Pancreatitis

• Perform a complete medication review to identify potential drug toxicity—incomplete drug history overlooks iatrogenic pancreatitis. 1
• Causative medications include azathioprine/6-mercaptopurine, valproic acid, and others. 2
• Onset can occur shortly after initial use or develop after years of therapy. 2

Hypertriglyceridemia

• Severe elevations in serum triglycerides (often >1000 mg/dL) can precipitate acute pancreatitis. 2, 6
• This etiology is both a potential cause and consequence of pancreatic inflammation. 2
• Measure lipid levels after the acute phase if etiology remains unclear—delayed lipid testing is a common error. 1
• Cases associated with hypertriglyceridemia demonstrate increased clinical severity and complications. 6

Hypercalcemia

• Elevated calcium can activate pancreatic enzymes prematurely, leading to autodigestion and inflammation. 2
• Measure calcium levels after the acute phase if etiology is unclear. 1

Anatomical Abnormalities

• Pancreas divisum and other pancreatic duct abnormalities can obstruct normal pancreatic drainage. 2
• Pancreatic tumors can occasionally present as acute pancreatitis, particularly in elderly patients with idiopathic disease. 2

Autoimmune Pancreatitis

• Immune-mediated form that may be associated with IgG4-related disease. 2

Infectious Causes

• Viral infections can occasionally trigger pancreatitis. 2

Trauma or Surgery

• Direct injury to the pancreas or post-surgical complications, particularly after abdominal or cardiac procedures. 2

Idiopathic Pancreatitis

• No more than 20-25% of cases should be classified as "idiopathic"—higher rates suggest inadequate workup. 1, 2
• The etiology should be determined in 75-80% of cases. 1
• For idiopathic cases, advanced evaluation may include endoscopic ultrasound to detect common bile duct stones or microlithiasis. 1
• Bile sampling may be used to assess for microlithiasis in patients with repeated attacks and no identified cause. 1
• Perform at least two good-quality ultrasound examinations before labeling as idiopathic, as gallstones are often missed initially. 2

Critical Diagnostic Pitfalls to Avoid

• Incomplete alcohol history: Failure to accurately document alcohol intake in units per week misses a major etiology. 1
• Premature closure on "idiopathic" diagnosis: More than 20-25% idiopathic cases indicates inadequate workup. 1
• Missing medication causes: Incomplete drug history overlooks iatrogenic pancreatitis. 1
• Delayed metabolic testing: Lipid and calcium levels should be measured after acute phase if etiology unclear. 1
• Single negative ultrasound: Gallstones require repeat imaging if initially not visualized. 1, 2