A 52-year-old man from Delhi presents with epigastric pain and hematemesis. Upper endoscopy reveals a duodenal ulcer. Which is the most common cause of peptic ulcer disease in this patient?

Explanation

## Most Common Cause of Peptic Ulcer Disease **Key Point:** Helicobacter pylori (H. pylori) infection accounts for approximately 60–90% of peptic ulcer disease worldwide, and remains the leading cause in India and developing nations. ### Epidemiology H. pylori is a gram-negative, microaerophilic bacterium that colonizes the gastric mucosa. In India, seroprevalence ranges from 40–60%, making it the dominant etiology of PUD. ### Pathophysiology 1. H. pylori colonizes the gastric antrum and corpus 2. Triggers chronic inflammation via CagA and VacA toxins 3. Increases gastric acid secretion and reduces bicarbonate secretion 4. Leads to mucosal damage and ulcer formation ### Relative Frequencies of PUD Causes | Cause | Frequency | Notes | |-------|-----------|-------| | H. pylori | 60–90% | Most common worldwide; endemic in India | | NSAIDs | 10–25% | Second most common; higher in elderly | | Zollinger-Ellison | 1–2% | Rare; associated with MEN-1 | | Crohn's disease | <1% | Causes ulcers but not primary PUD | | Idiopathic | 5–10% | Diagnosis of exclusion | **High-Yield:** In any Indian patient with peptic ulcer, H. pylori infection must be ruled out first. Eradication therapy (triple or quadruple regimen) is the standard of care. **Clinical Pearl:** H. pylori eradication rates in India are lower (70–80%) due to high antibiotic resistance; hence, susceptibility testing or empirical quadruple therapy is often preferred. ### Diagnostic Confirmation - **Serology (IgG antibodies):** Screening tool; remains positive even after eradication - **Stool antigen:** Non-invasive, useful for post-treatment confirmation - **Urea breath test:** Gold standard for diagnosis and post-eradication assessment - **Endoscopic biopsy:** Rapid urease test, histology, culture