For a study, researchers sought to comprehensively assess the existing data on Helicobacter pylori-negative chronic gastritis, including natural history, treatments, and outcomes. A comprehensive search of the MEDLINE and EMBASE databases yielded articles with information on the prevalence, treatment, or consequences of Helicobacter pylori-negative gastritis. All original research publications from human studies published before October 31, 2021, were considered.

There were 54 studies in all, including eosinophilic gastritis (n = 9), autoimmune gastritis (n = 11), collagenous gastritis (n = 16), focally increased gastritis (n = 6), lymphocytic gastritis (n = 5) and other reasons such as idiopathic gastritis and chronic renal failure linked (n = 7). Except for collagenous gastritis, which mostly featured case reports and case series, most of the included studies were either cross-sectional or longitudinal cohorts.

The frequency of juvenile eosinophilic gastritis ranged between 5 and 7/100,000, and patients have a usually positive result, with 50% – 70% clinical and histological response to either corticosteroids or elimination diets. Autoimmune and collagenous gastritis are exceedingly uncommon conditions that frequently appear with refractory iron-deficient anemia, but lymphocytic gastritis is rather prevalent (10%–45%) in children with celiac disease. There is a dearth of evidence on the treatments and outcomes of autoimmune, collagenous, and focally increased gastritis, with minimal data suggesting a poor response to therapy in the first two diagnoses. Helicobacter pylori-negative gastritis had been described infrequently, mostly in small cohorts, mixed adult-pediatric cohorts, or rare case reports. In addition, because common symptoms are not always specific, resulting in an endoscopic test, the real incidence of these different illnesses may be underestimated and underreported.