Pancreatitis

Pancreatitis is a medical condition defined by inflammation of the pancreas, an organ located behind the stomach that is responsible for producing digestive enzymes and important hormonal substances such as insulin and glucagon. The disorder ranges in severity from mild, self-limiting episodes to life-threatening disease with multisystem involvement. Clinically, pancreatitis is broadly categorised into acute and chronic forms, each with distinct causes, manifestations and long-term implications.

Types of Pancreatitis and Clinical Presentation

Acute pancreatitis refers to sudden inflammation of the pancreas, often presenting with severe upper abdominal pain situated in the epigastrium or the left upper quadrant. The pain commonly radiates to the back and is frequently accompanied by nausea and vomiting, which may worsen on eating. Fever may also occur. Most acute episodes resolve within a few days with supportive management.
Chronic pancreatitis is characterised by persistent inflammation leading to irreversible structural damage. Recurrent episodes of abdominal pain, progressive weight loss, steatorrhoea and diarrhoea are notable features due to impaired secretion of digestive enzymes. Over time, endocrine dysfunction may occur, predisposing affected individuals to diabetes mellitus. Chronic pancreatitis develops gradually, commonly between the ages of 30 and 40, and is more prevalent in men.
Physical examination varies widely depending on the severity of inflammation and the presence of complications. Pain is typically disproportionate to abdominal tenderness on palpation. Systemic signs such as tachycardia, low blood pressure from dehydration or bleeding, and reduced bowel sounds due to reflex ileus may be observed. Jaundice may result from obstruction of the bile duct, while prolonged disease increases the risk of pancreatic cancer.

Causes and Risk Factors

Gallstones and alcohol misuse account for the vast majority of pancreatitis cases. Gallstones obstructing the common bile duct, especially at the junction with the pancreatic duct, represent the single most frequent cause of acute pancreatitis. Heavy and long-term alcohol consumption is the most common cause of chronic pancreatitis and a significant contributor to recurrent acute episodes.
Other recognised causes include:

• Trauma to the abdomen, including surgical or endoscopic injury.
• Medications, including statins, ACE inhibitors, oestrogen-containing therapies, diuretics, antiretroviral agents, valproic acid and certain oral hypoglycaemic agents. Mechanisms range from direct pancreatic toxicity to metabolic disturbances such as hypertriglyceridaemia.
• Infections, notably mumps, but also a wider range of viral, bacterial and parasitic agents.
• Metabolic disorders, including hyperlipidaemia, hypercalcaemia and hypothermia.
• Genetic conditions, including cystic fibrosis, hereditary pancreatitis involving mutations in trypsinogen or SPINK1, and congenital abnormalities such as pancreas divisum.
• Autoimmune pancreatitis, vasculitis and exposure to toxins.
• ERCP (endoscopic retrograde cholangiopancreatography), a diagnostic and therapeutic procedure that can trigger pancreatitis in susceptible individuals.
• Tobacco smoking, which independently increases the risk of both acute and chronic pancreatitis.

A widely used mnemonic for causes of pancreatitis is GET SMASHED, covering gallstones, ethanol, trauma, steroids, mumps, autoimmune conditions, scorpion sting, hyperlipidaemia or hypercalcaemia, ERCP and various drugs.

Pathophysiology and Complications

Pancreatitis arises from inappropriate activation of pancreatic enzymes within the gland, leading to autodigestion of pancreatic tissue. This process triggers local inflammation, vascular injury and systemic inflammatory responses. In severe cases, pancreatic and peripancreatic necrosis, infection and multi-organ dysfunction may follow.
Complications of acute pancreatitis include:

• Shock, circulatory collapse and severe dehydration.
• Metabolic disturbances, including hypocalcaemia and hyperglycaemia.
• Renal impairment, resulting from hypovolaemia and systemic inflammation.
• Respiratory complications, including acute respiratory distress syndrome, pleural effusion, atelectasis and pneumonitis caused by circulating pancreatic enzymes.
• Intra-abdominal hypertension and abdominal compartment syndrome, which may require surgical intervention.

Late complications involve recurrent attacks, chronic inflammation and the formation of pancreatic pseudocysts—collections of pancreatic fluid enclosed by fibrous tissue. These may rupture, bleed, become infected or obstruct the bile duct. Acute necrotising pancreatitis may progress to pancreatic abscess formation, particularly when multiple pseudocysts are present.
Chronic pancreatitis carries additional long-term risks such as malabsorption, secondary diabetes and pancreatic malignancy.

Diagnosis

Diagnosis requires fulfilment of at least two of the following criteria:

• Characteristic abdominal pain, typically acute onset and radiating to the back.
• Serum amylase or lipase levels at least three times the upper limit of normal. Lipase is generally preferred due to its greater sensitivity, specificity and longer half-life.
• Imaging findings consistent with pancreatitis, identified through CT scanning, magnetic resonance imaging, abdominal ultrasound or endoscopic ultrasound.

In chronic pancreatitis, enzyme levels may be normal due to decreased functional pancreatic tissue.
Differential diagnoses include cholecystitis, peptic ulcer disease, choledocholithiasis, bowel obstruction, mesenteric ischaemia, hepatitis and other causes of acute abdominal pain.

Management

Management strategies depend on severity and underlying causes:

• Initial treatment for acute pancreatitis involves aggressive intravenous fluid resuscitation, effective pain control and monitoring for complications.
• Nutritional support may be required. Severe cases may necessitate temporary nasogastric feeding if oral intake is not tolerated.
• Antibiotics may be used when infection is suspected, although routine prophylaxis is not recommended.
• ERCP is indicated when gallstones are implicated, enabling removal of obstructing stones.
• Cholecystectomy is typically recommended to prevent recurrence in gallstone-related pancreatitis.
• Chronic pancreatitis management includes long-term dietary modification, avoidance of alcohol, pancreatic enzyme replacement therapy and, in severe cases, surgical intervention to remove diseased pancreatic tissue or relieve ductal obstruction.

Epidemiology and Historical Background

Pancreatitis represents a significant global health burden. In 2015, approximately 8.9 million cases were reported worldwide, resulting in more than 130,000 deaths—an increase from earlier decades. Acute pancreatitis affects about 30 per 100,000 people annually, while chronic pancreatitis develops in about 8 per 100,000 individuals each year and affects roughly 50 per 100,000 people in the United States.
The condition is more common in men, particularly chronic pancreatitis associated with alcohol misuse. Childhood cases remain uncommon.
Acute pancreatitis was first documented on autopsy in 1882, whereas chronic pancreatitis was described in medical literature in 1946, marking the distinction between the two forms.
Pancreatitis remains a complex and potentially serious inflammatory disorder with considerable clinical variation. Advances in diagnostic modalities, improved understanding of pathophysiology and refinement of treatment strategies continue to shape modern management and reduce morbidity and mortality.