Snapshot A 55-year-old man presents to his primary care physician for intermittent epigastric pain for the past few months. He reports having sudden-onset nausea and bloating episodes as well. His other past medical history includes chronic back pain, for which he takes ibuprofen regularly. He smokes cigarettes and drinks alcohol on a daily basis. He is prescribed a proton pump inhibitor, instructed to cut back on alcohol, and scheduled for an upper endoscopy. Introduction Overview inflammation of the gastric mucosa often with erosive changes subtypes are acute gastritis due to NSAID use, alcohol, severe illness, or H. pylori infection chronic gastritis atrophic gastritis due to autoantibodies to gastric parietal cells nonatrophic gastritis due to NSAID use, alcohol, or other factors Associated conditions atrophic gastritis other autoimmune diseases i.e., pernicious anemia and diabetes mellitus Epidemiology Demographics adults chronic gastritis is very common Risk factors east Asian heritage drug use prior history of H. pylori autoimmune disease ETIOLOGY Pathogenesis mechanism atrophic gastritis loss of parietal cells atrophy of gastric mucosa nonatrophic gastritis inflammation of gastric mucosa Presentation History may be asymptomatic sudden-onset nausea vomiting hematemesis melena bloating Symptoms common symptoms location epigastric pain aggravating factor NSAID use alcohol use Physical exam palpation may have epigastric tenderness Imaging No imaging indicated Studies Serum labs normal gastrin level vitamin B12 may be decreased in atrophic gastritis H. pylori antibody testing does not distinguish between current or past infection Invasive studies endoscopy indications all patients most accurate test findings inflammation of gastric mucosa erosions ulcers urease breath test indication test for H. pylori used to diagnose and confirm eradication of the infection H. pylori stool antigen test indication test for H. pylori used to diagnose and confirm eradication of the infection Histology biopsy from endoscopy findings atrophy chronic inflammation intestinal metaplasia Differential Zollinger-Ellison syndrome key distinguishing factors symptoms of gastritis that aren’t responsive to therapy elevated serum gastrin levels Treatment Nonoperative lifestyle changes avoid exacerbating agents indication all patients proton-pump inhibitors or H2 blockers indication all patients except those with atrophic gastritis prophylaxis for patients at risk for stress ulcers head trauma intubation burns coagulopathy H. pylori eradication therapy indication H. pylori positive disease modalities triple therapy proton pump inhibitor clarithromycin amoxicillin or metronidazole quadruple therapy proton pump inhibitor bismuth subcitrate metronidazole tetracycline vitamin B12 supplementation indication atrophic gastritis Complications Gastric cancer Gastrointestinal bleeding