Diphtheroid peritonitis associated with continuous ambulatory peritoneal dialysis

Five patients on continuous ambulatory peritoneal dialysis (CAPD) developed peritonitis caused by diphtheroid bacteria. Peritoneal catheter exit site inflammation and/or discharge preceded all cases and relapses were common. Antimicrobial therapy alone failed to eradicate the bacteria and peritoneal catheter removal was required before peritonitis resolved. Laboratory culture of the diphtheroid bacteria was difficult and prolonged incubation was often necessary. Diphtheroid bacteria are important opportunistic pathogens in immunocompromised patients and should be carefully sought for in all cases of culture-negative CAPD-associated peritonitis.