Relapsing peritoneal dialysis‑associated peritonitis caused by Pseudomonas oryzihabitans with concurrent tunnel infection: a case report and literature review.

Peritoneal dialysis (PD)-associated peritonitis is linked to an increased risk of catheter removal and PD discontinuation, with these risks occurring more frequently in relapsing peritonitis than in primary peritonitis. Relapses are often attributed to persistent infection originating from the PD catheter, including tunnel infection (TI). Although Pseudomonas oryzihabitans is a commensal bacterium and recognized opportunistic pathogen, only a limited number of cases of P. oryzihabitans peritonitis—and none involving relapsing peritonitis with concurrent TI—have been reported. A 73-year-old Japanese man undergoing PD presented with abdominal pain, fatigue, fever, and decreased PD fluid drainage. He was diagnosed with PD-associated peritonitis caused by P. oryzihabitans, which was preceded by a persistent exit-site infection due to different organisms. A 21-day course of antimicrobial therapy combined with peritoneal lavage led to clinical improvement. However, 27 days after completing treatment, he developed relapsing peritonitis due to P. oryzihabitans, complicated by TI suspected on computed tomography. However, the patient declined catheter removal and chose outpatient intraperitoneal antibiotics. The relapse resolved, but persistent yellow drainage prompted cuff-shaving surgery. We present a case of peritonitis caused by P. oryzihabitans, initially presenting with exit site infection and later complicated by TI at recurrence, that was successfully treated without PD catheter removal. This case suggests that cuff-shaving combined with appropriate antimicrobial therapy may be an effective treatment option for P. oryzihabitans peritonitis when the peritonitis and catheter infection are not caused by the same organism.