How should gastritis be evaluated and managed, including workup, H. pylori eradication therapy, and treatment of NSAID‑induced gastritis?

Gastritis: Evaluation and Management

Diagnostic Workup

All suspected gastritis requires endoscopic biopsy for histopathological confirmation, as clinical symptoms alone are insufficient for diagnosis. 1

• Obtain topographical biopsies from both the gastric body and antrum/incisura in separately labeled containers to assess distribution and extent of inflammation 1
• Target any additional mucosal abnormalities observed during endoscopy for biopsy 1
• Recognize that intestinal metaplasia on histology almost invariably indicates underlying atrophic gastritis, even when atrophy is not explicitly documented by the pathologist 1
• Do not rely on endoscopic appearance alone—histopathologic confirmation is mandatory because normal-appearing mucosa can harbor atrophy 1

Mandatory H. pylori Testing and Eradication

Every patient with confirmed gastritis must be tested for H. pylori infection using non-serological methods (urea breath test, stool antigen test, or histology), and if positive, receive eradication therapy. 1, 2

Testing Strategy

• Use urea breath test or monoclonal stool antigen test for initial diagnosis 2
• Do not use serologic testing as it remains positive after eradication and cannot confirm treatment success 2
• Ensure patients are off PPI therapy for at least 2 weeks before testing to avoid false-negative results 2

Eradication Protocol

Bismuth quadruple therapy for 14 days is the first-line treatment due to increasing antibiotic resistance. 2

• Regimen includes: high-potency PPI + bismuth subsalicylate + metronidazole + tetracycline 2
• Concomitant 4-drug therapy is an alternative when bismuth is unavailable 2
• Prioritize "Access group" antibiotics (amoxicillin, tetracycline, metronidazole) over "Watch group" antibiotics (clarithromycin, levofloxacin) to minimize resistance 2
• Do not use antibiotic courses shorter than 14 days as this results in treatment failure 2

Confirmation of Eradication

• Test for successful eradication 4-6 weeks after completing antibiotic therapy using non-serological methods 2
• Confirm the patient has been off PPI therapy for at least 2 weeks before testing 2

NSAID-Induced Gastritis Management

Risk Stratification and Prevention

The best method to prevent NSAID-related ulcer complications is to avoid NSAID use; non-NSAID analgesics should be first-line treatment for degenerative arthritis or non-inflammatory pain. 3

When NSAIDs are required, stratify patients by risk:

• Low risk (no risk factors): Use least ulcerogenic NSAID at lowest effective dose 3
• Moderate risk (1-2 risk factors): NSAID + antisecretory agent or misoprostol or COX-2 inhibitor 3
• High risk (≥3 risk factors or concomitant aspirin/steroids/anticoagulants): COX-2 inhibitor alone with steroids, plus misoprostol with warfarin, or plus PPI or misoprostol with aspirin 3
• Very high risk (history of ulcer complications): Avoid all NSAIDs if possible, or COX-2 inhibitor plus PPI and/or misoprostol 3

H. pylori and NSAIDs Interaction

H. pylori infection increases the risk of upper gastrointestinal complications in NSAID users by two- to fourfold, making testing and eradication mandatory before starting regular NSAID therapy. 3

• Test all patients requiring regular NSAID therapy for H. pylori 3
• H. pylori eradication is beneficial before starting NSAID treatment and mandatory in patients with a peptic ulcer history 3
• For aspirin users with a history of gastroduodenal ulcer, H. pylori eradication should be performed; the long-term incidence of peptic ulcer bleeding is low after successful eradication even without gastroprotective treatment 3
• Eradication before starting NSAIDs reduces subsequent ulcer risk (from 26% to 7% over 8 weeks in one study) 3

Autoimmune Gastritis-Specific Management

When histology shows corpus-predominant atrophy:

• Check antiparietal cell antibodies and anti-intrinsic factor antibodies to confirm autoimmune etiology 1
• Measure vitamin B12 levels and obtain complete blood count to detect macrocytic anemia 1
• Assess iron status because hypochlorhydria impairs iron absorption and can lead to iron-deficiency anemia 1
• Screen for type 1 gastric neuroendocrine tumors with upper endoscopy, as hypergastrinemia drives NET development 1
• Remove small NETs endoscopically and follow with surveillance endoscopy every 1-2 years depending on tumor burden 1

Acid Suppression Therapy

For severe gastritis, high-potency PPIs such as esomeprazole 20-40 mg or rabeprazole 20 mg twice daily are first-line treatment, taken 30 minutes before meals for optimal effectiveness. 2

• Lansoprazole 30 mg twice daily is an alternative high-potency option 2
• Treatment duration should be at least 8 weeks for healing of erosive changes 2
• Premature discontinuation before 8 weeks prevents adequate mucosal healing 2

Critical PPI Caveat

Long-term PPI treatment in H. pylori-positive patients accelerates progression to corpus-predominant atrophic gastritis; eradication of H. pylori is necessary before initiating chronic PPI therapy. 3, 2

• Eradication heals gastritis and prevents progression to atrophic gastritis, though evidence that this reduces gastric cancer risk is lacking 3

Surveillance Strategy for Atrophic Gastritis

For advanced atrophic gastritis (extensive anatomic distribution and/or severe histologic grade), perform surveillance endoscopy every 3 years. 1

• Use enhanced imaging techniques (electronic chromoendoscopy) to identify subtle mucosal changes and guide targeted biopsies 1
• For autoimmune gastritis, a 3-year interval is reasonable for advanced disease 1
• Patients with newly diagnosed pernicious anemia who have not had recent endoscopy should undergo endoscopy with topographical biopsies to confirm corpus-predominant atrophy, stratify cancer risk, and exclude prevalent gastric neoplasia including NETs 1

Common Pitfalls to Avoid

• Do not rely on symptom resolution without confirming H. pylori eradication, as this allows persistent infection 2
• Do not prescribe long-term PPIs without first eradicating H. pylori, as this accelerates progression to atrophic gastritis 2
• Do not use inadequate PPI dosing or incorrect timing (must be 30 minutes before meals) 2
• Do not use serologic H. pylori testing in atrophic gastritis, as advanced atrophy reduces antibody titers and may yield false-negative results 1
• Delaying H. pylori treatment allows continued mucosal damage and progression toward atrophy 2