Abstract
Vonoprazan, a potassium-competitive acid blocker, is effective at treating acid-related gastrointestinal disorders but has been linked to gastric mucosal redness, a novel condition. This report describes two cases of vonoprazan-associated mucosal redness. Case 1 involved a 73-year-old woman who developed longitudinal erythema and mild mucosal changes after starting vonoprazan seven years ago. Case 2 involved a 70-year-old man who exhibited significant erythema and atrophic gastritis after seven months of treatment. In both cases, the pathological findings included hemorrhage in the superficial mucosa, highlighting that microhemorrhage may be the corresponding pathological finding for vonoprazan-associated mucosal redness.