Article in Japanese

Persistent Helicobacter pylori infection following primary infection-induced acute gastric mucosal lesions in a school-age child

Tomoki Sato^1）, Rika Okano^1）

Helicobacter pylori infection rarely results in persistent infection after school age, and acute gastric mucosal lesions （AGML） commonly occur during primary H. pylori infection with transient colonization. This study reports the case of a 9-year-old girl presenting with abdominal pain and diarrhea. Initially, she developed vomiting and diarrhea, followed by persistent vomiting and severe abdominal pain, from which she was hospitalized. Abdominal ultrasonography revealed circumferential wall thickening predominantly in the gastric antrum, and particularly in the submucosal layer. Upper gastrointestinal endoscopy demonstrated multiple erosions and superficial ulcers in the antrum, leading to an AGML diagnosis.
Treatment with fasting and proton pump inhibitors （PPI） resulted in symptom improvement. Urea breath test （UBT） was positive at admission, but became negative two months after onset （14 days after PPI discontinuation）. However, subsequent UBTs at 6 and 9 months were positive. Follow-up endoscopy at 9 months showed nodular gastritis, and H. pylori was cultured from gastric mucosa specimens. The patient was diagnosed with persistent H. pylori infection and received eradication therapy based on antimicrobial susceptibility testing.
This case demonstrates that despite temporary UBT negativity following AGML, persistent H. pylori infection may occur. Therefore, continued monitoring is essential even in cases of apparent spontaneous elimination, and appropriate eradication therapy should be administered when persistent infection is confirmed.

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1）Department of Pediatrics, Hiroshima City Funairi Citizens Hospital

Key words	Helicobacter pylori, acute gastric mucosal lesions, nodular gastritis, spontaneous eradication，persistent infection
Received	August 25, 2025
Accepted	December 23, 2025

38 (1)：5─12,2026