Atypical acute Helicobacter pylori infection without atrophic gastritis: A case report.

A 64-year-old Chinese man visited our clinic's health-screening center. The patient tested negative for Helicobacter pylori (HP) infection in his home country, but at this visit, anti-HP antibodies of 5 U/mL and a urea breath test (UBT) result of 48.6‰ were detected. Upper gastrointestinal endoscopy showed no atrophic gastritis, and a regular arrangement of collecting venules was observed. Since a false-positive UBT was also considered, Smart Gene testing was performed, which confirmed the HP positivity. As no clarithromycin resistance mutation was detected, Japan's first-line eradication regimen was prescribed. The eradication test result was a UBT of 0.1‰, confirming successful HP eradication.