Helicobacter pylori Gastritis as an Initial Presentation of Evolving Autoimmune Gastritis: A Report of Two Cases.

We herein report two cases of evolving autoimmune gastritis (AIG) that were initially diagnosed as active Helicobacter pylori gastritis. Both presented with swollen gastric areas and erythema in the context of a current H. pylori infection. One patient progressed to overt AIG after H. pylori eradication therapy, while the other progressed after the spontaneous disappearance of H. pylori infection. At the time of the AIG diagnosis, the antral mucosa showed atrophic regression, while the corpus mucosa showed severe atrophy. Therefore, when swollen gastric areas with erythema are observed during active H. pylori gastritis, AIG should be considered.