Peptic Ulcer Disease

Peptic ulcer disease is a breach in the mucosa of the stomach or duodenum that extends through the muscularis mucosae, produced by the caustic action of gastric acid and pepsin when mucosal defences are overwhelmed. The two dominant causes are infection with Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs (NSAIDs), and the disease is a classic illustration of an imbalance between aggressive and protective forces at the mucosal surface.

Definition

A mucosal defect of the stomach or duodenum penetrating through the muscularis mucosae into the submucosa or deeper, resulting from acid-peptic injury when mucosal protection is compromised, most often by Helicobacter pylori infection or NSAID use.

Scope

This entry covers the pathology of gastric and duodenal ulceration: the morphology of the ulcer, the mucosal-defence-versus-aggression model, the central roles of Helicobacter pylori and NSAIDs, and the principal complications. It is a reference description of disease mechanism and tissue change, not a treatment protocol.

Core questions

• How does the balance between mucosal defence and acid-peptic aggression determine ulcer formation?
• By what mechanisms do Helicobacter pylori and NSAIDs cause ulceration?
• What tissue changes and complications distinguish chronic peptic ulcers?

Key concepts

• Acid-peptic mucosal injury
• Mucosal defence versus aggression balance
• Helicobacter pylori infection
• NSAID-induced mucosal injury
• Gastric versus duodenal ulcer
• Ulcer complications (bleeding, perforation, obstruction)

Mechanisms

A peptic ulcer forms when the corrosive effect of luminal acid and pepsin exceeds the capacity of the mucosa to defend and repair itself. Helicobacter pylori, a gram-negative spiral bacterium identified in gastric mucosa by Marshall and Warren, colonises the antrum and provokes chronic active gastritis that alters acid secretion and weakens mucosal integrity, predisposing to duodenal and gastric ulcers (Marshall & Warren 1984; Malfertheiner 2009). NSAIDs cause injury by inhibiting cyclooxygenase and depleting protective prostaglandins, reducing mucus and bicarbonate secretion and mucosal blood flow. The resulting ulcer is typically a sharply demarcated, round-to-oval defect with a clean base; chronic ulcers show four histologic zones (necrotic debris, inflammatory exudate, granulation tissue, and fibrotic scar). Penetration into underlying vessels or through the wall produces the major complications of haemorrhage and perforation (Malfertheiner 2009).

Clinical relevance

Peptic ulcer disease underlies a substantial share of upper gastrointestinal bleeding and perforation and connects directly to the recognition of Helicobacter pylori as a treatable infection. Understanding its pathology supports interpretation of gastric biopsies and the rationale behind eradication strategies described in consensus statements; the content here is educational and does not constitute individualized medical advice (Malfertheiner 2017).

Epidemiology

Although lifetime risk remains appreciable, the incidence of peptic ulcer disease has declined in many regions with falling Helicobacter pylori prevalence and acid-suppressive therapy, even as NSAID-related ulceration persists. The burden varies with the regional prevalence of Helicobacter pylori infection and patterns of NSAID use (Malfertheiner 2009).

Evidence & guidelines

Contemporary understanding draws on narrative reviews of disease mechanism (Malfertheiner 2009) and on consensus guidance such as the Maastricht V/Florence Consensus Report on Helicobacter pylori management, which frames the infection's role in ulcer disease (Malfertheiner 2017). These are cited as the basis for the pathophysiologic account rather than as prescriptive instructions.

History

For much of the twentieth century peptic ulceration was attributed chiefly to stress and acid hypersecretion. The 1983-1984 observation by Warren and Marshall of curved bacilli in gastric mucosa, and the demonstration that this organism (later named Helicobacter pylori) caused gastritis and ulceration, overturned that view and reframed peptic ulcer disease as an infectious and curable condition, work recognised with the 2005 Nobel Prize in Physiology or Medicine (Marshall & Warren 1984).

Key figures

• Barry Marshall
• Robin Warren
• Peter Malfertheiner

Seminal works

• marshall-warren-1984
• malfertheiner-2009
• malfertheiner-2017-maastricht

Frequently asked questions

What are the two main causes of peptic ulcer disease?

Infection with Helicobacter pylori and the use of nonsteroidal anti-inflammatory drugs (NSAIDs) account for the large majority of peptic ulcers; both shift the balance between mucosal aggression and defence toward injury.

How does a peptic ulcer differ from gastritis?

Gastritis is inflammation of the gastric mucosa, whereas a peptic ulcer is a discrete defect that penetrates through the muscularis mucosae into deeper layers of the wall, with a characteristic chronic ulcer architecture.