To raise awareness of autoimmune gastritis (AIG), which is a well-established phenomenon in adults but is seldom documented in kids. The literature currently discusses AIG in juvenile patients who simultaneously have other autoimmune diseases, which typically predate the diagnosis of AIG and appear with unexplained anaemia. There have also been case reports of people with immunodeficiencies and AIG who develop stomach cancer. AIG is a histopathologic diagnosis characterised by a persistent inflammatory process with parietal cell loss, intestinal metaplasia, and enterochromaffin-like cell hyperplasia. These patients’ care involves nutritional supplementation as well as routine monitoring endoscopy with biopsy to look for metaplastic and dysplastic alterations. Researchers searched the pathology database at Children’s Hospital Los Angeles (CHLA) for patients with AIG as the final diagnosis and those with AIG in the differential diagnosis. All instances found were chosen because they met not only the histopathologic but also the biochemical criteria for this disease. Two of the three patients were sent to gastroenterology for assessment of iron deficiency anaemia in the setting of diabetes mellitus and Addison’s illness, and diabetes mellitus and Hashimoto’s thyroiditis, respectively. Iron replacement treatment was administered to both individuals. The third patient arrived with symptomatic anaemia and was diagnosed with pernicious anaemia in the absence of any other autoimmune diseases. Oral vitamin supplements proved to be effective in her treatment. Serial gastric biopsies in this case revealed steady intestinal metaplasia with no signs of dysplasia.

Although AIG is uncommon in children, paediatric gastroenterologists and pathologists should be on the lookout for it in patients with a history of autoimmune diseases and/or pernicious anaemia.