Peptic ulcer disease - causes, symptoms, diagnosis, treatment, pathology

Peptic ulcer disease refers to sores in the stomach (gastric ulcers) or duodenum (duodenal ulcers), with duodenal ulcers being more common. The gastrointestinal tract is lined with mucosa, consisting of an epithelial layer for absorption and secretion, a lamina propria with blood and lymph vessels, and a muscularis mucosa for muscle contraction. The stomach has four regions: cardia, fundus, body, and pyloric antrum, each with specific cell types secreting mucus, hydrochloric acid, pepsinogen, and gastrin. The duodenum also has Brunner glands that secrete bicarbonate-rich mucus.

The stomach and duodenal mucosa are protected from digestive enzymes and hydrochloric acid by a mucus coating and bicarbonate ions, which neutralize acid. The stomach has a thicker mucus layer than the duodenum due to constant acid exposure. Blood flow to these areas also provides bicarbonate. Prostaglandins further stimulate mucus and bicarbonate secretion, promote vasodilation and new epithelial cell growth, and inhibit acid secretion, all contributing to mucosal protection.

The primary cause of gastric and duodenal ulcers is H. pylori bacterial infection, especially in low-income countries. H. pylori release adhesins and proteases that damage mucosal cells, leading to ulcers. Another significant cause is the prolonged use of nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, which inhibit prostaglandin synthesis, leaving the gastric mucosa vulnerable. A rare cause is Zollinger-Ellison syndrome, a tumor (gastrinoma) that secretes abnormal amounts of gastrin, leading to excess hydrochloric acid production and ulcer formation.

Peptic ulcers are typically small, round, 'punched out' holes with a clean base due to acid secretions and churning. Beneath the base, there's scar tissue and blood vessels. Gastric ulcers commonly form in the lesser curvature of the antrum. Duodenal ulcers usually develop right after the pyloric sphincter and are often accompanied by Brunner gland hypertrophy as the body attempts to produce more protective mucus.

Deep ulcers can erode into blood vessels, causing dangerous bleeding. Hemorrhage into the gastrointestinal tract can lead to shock, especially if large arteries like the left gastric artery (for gastric ulcers) or gastroduodenal artery (for duodenal ulcers) are involved. Another severe complication is perforation, where the ulcer erodes through the stomach or duodenal wall, allowing gastrointestinal contents into the sterile peritoneal space, irritating the phrenic nerve and causing referred shoulder pain. Rarely, long-standing duodenal ulcers near the pyloric sphincter can cause gastric outlet obstruction due to edema or scarring, leading to nausea and vomiting.

The main symptom of peptic ulcers is epigastric pain, an aching or burning in the upper abdomen. Other symptoms include bloating, belching, and vomiting. Gastric ulcer pain typically increases with eating, while duodenal ulcer pain decreases. Diagnosis involves upper endoscopy to visualize the ulcer and perform a biopsy to check for malignant cells or H. pylori infection. Treatment depends on the cause; H. pylori infections are treated with antibiotics and acid-lowering medications like proton pump inhibitors. It's recommended to avoid NSAIDs, alcohol, tobacco, and caffeine, and in severe cases, surgery may be necessary.