Chronic Gastritis
by Samreen Khan
1. Investigations
1.1. CBC
1.2. serum B12 levels
1.3. antiparietal cell and anti-intrinsic factor antibodies
1.4. H. pylori tests: urea breath test, stool antigen test, serology
1.5. endoscopy: visualize gastric mucosa for erosions, atrophy or ulcers
1.6. biopsy if needed
2. Treatment
2.1. H. pylori eradication: PPI + clarithromycin + amoxicillin
2.2. Autoimmune gastritis: vitamin B12 supplements
2.3. symptomatic relief: proton pump inhibitors (eg: omeprazole) or H2 receptor antagonists
2.4. avoid irritants: stop NSAIDS and limit alcohol
2.5. surgical resection: needed in complication such as gastric cancer or severe ulceration
3. **Prevention**
3.1. good hygiene (handwashing, proper food preparation)
3.2. avoid excess alcohol, smoking, chronic NSAID use
3.3. early screening for at risk populations for H. pylori or pernicious anemia
4. definition
4.1. prolonged inflammation of gastric mucosa
4.1.1. complications: gastric ulcers, gastric cancer or peptic ulcer disease
5. causes
5.1. infectious
5.1.1. Helicobacter pylori infection (most common)
5.2. autoimmune
5.2.1. autoimmune gastritis
5.2.1.1. pernicious anemia
5.3. chemical
5.3.1. chronic NSAID use, alcohol use, bile reflux
5.4. other causes
5.4.1. radiation, Crohn's disease, sarcoidosis, Zollinger-Ellison syndrome
6. Pathogenesis
6.1. H pylori gastritis
6.1.1. chronic inflammation by immune responses
6.1.1.1. damage to gastric epithelium, atrophy, intestinal metaplasia, dysplasia
6.1.2. cytotoxins (CagA and VacA) and oxidative stress = progression of disease
6.2. Autoimmune gastritis
6.2.1. autoantibodies destroy parietal cells and reduce IF
6.2.1.1. hypochlorhydria, impaired vitamin B12 absorption, megaloblastic anemia
6.3. Chemical gastritis
6.3.1. prolonged NSAID use disrupts the protective mucus barrier
6.3.1.1. inflammation and injury