Expansion
Helicobacter pylori and NSAIDs account for the great majority
Expansion
Causes
- Helicobacter pylori: about 90 per cent of duodenal and 70 per cent of gastric ulcers. Antral infection raises gastrin and acid, favouring duodenal ulcers; body infection causes atrophy and reduced acid, favouring gastric ulcers and carcinoma
- NSAIDs: block prostaglandin-mediated mucosal defence
- Zollinger-Ellison syndrome: gastrinoma, causing multiple and distal ulcers
- Smoking, severe stress (Curling ulcers after burns, Cushing ulcers with raised intracranial pressure)
Complications
- Haemorrhage: a posterior duodenal ulcer erodes the gastroduodenal artery; a lesser curve gastric ulcer erodes the left gastric artery
- Perforation: an anterior duodenal ulcer perforates into the peritoneal cavity, giving free gas under the diaphragm
- Gastric outlet obstruction from scarring
- Malignancy: gastric ulcers require biopsy since carcinoma can ulcerate; duodenal ulcers are essentially never malignant
The anterior and posterior rule follows directly from anatomy: the gastroduodenal artery lies behind the first part of the duodenum, while the anterior surface faces the free peritoneal cavity.