146. Pancreatitis - classification, etiology, pathogenesis, clinical manifestations.

Pancreatitis - classification, etiology, pathogenesis, and clinical manifestations.

Pancreatitis is inflammation of the pancreas, which can be acute (sudden, reversible) or chronic (progressive, leading to irreversible damage and fibrosis).

Classification

1. 1 Acute pancreatitis

• Sudden inflammation, potentially reversible.
• May be mild (edematous) or severe (necrotizing).

1. 2 Chronic pancreatitis

• Progressive inflammatory disease.
• Leads to permanent structural damage, exocrine and endocrine dysfunction.

Etiology

Acute pancreatitis

• Gallstones (most common cause in many countries).
• Alcohol abuse (second most common).
• Hypertriglyceridemia.
• Hypercalcemia.
• Drugs (e.g., azathioprine, valproic acid).
• Post-ERCP (endoscopic retrograde cholangiopancreatography).
• Trauma.

Chronic pancreatitis

• Long-term alcohol abuse (most common).
• Recurrent acute pancreatitis.
• Genetic mutations (e.g., PRSS1 in hereditary pancreatitis).
• Obstructive causes (e.g., strictures, tumors).

Pathogenesis

Acute pancreatitis

1. Premature activation of pancreatic proenzymes (e.g., trypsinogen → trypsin) inside pancreatic acinar cells.
2. Activated enzymes cause autodigestion of pancreatic tissue.
3. Inflammatory response → interstitial edema, fat necrosis, hemorrhage.
4. Systemic inflammatory response syndrome (SIRS) → possible multi-organ failure.

Chronic pancreatitis

1. Repeated episodes of pancreatic inflammation.
2. Progressive replacement of pancreatic parenchyma with fibrous tissue.
3. Loss of exocrine function (malabsorption) and endocrine function (diabetes).