A Case of <i>Capnocytophaga canimorsus</i> Sepsis which Presented with Multiple Arthritis and a Generalized Rash

Abstract

A previously healthy 47-year-old male car driver visited our hospital because of 4-day history of high fever and multiple arthralgia of the major joints. Laboratory data showed a high level of CRP (25.1mg/dL), severe thrombocytopenia (18,000/μL), and liver dysfunction (AST 320U/L, ALT 772U/L). Physical examination revealed polyarthritis of the shoulders, elbows, knee joints, ankles, and hip joints. A pinkish macro rash was visible on the lower abdomen, lower extremities, and foot arches. Small black crusts on his right index finger with little discharge were incidentally found, and the patient reported that he had been bitten by his dachshund one day before the onset of the fever. Soon after admission, he was given platelet transfusion, low-molecular-weight heparin and Imipenem/Cilastatin (IPM/CS) under the tentative diagnosis of sepsis. Gram-negative thin rod-shaped bacteria were observed in the initial blood cultures after 48 hours, which was identified as Capnocytophaga canimorsus by mass spectrometry, PCR and sequence analysis of 16S rRNA gene and gyrB gene. IPM/CS was continued for 14 days. Physical symptoms such as fever, rash and multiple arthritis improved within 10 days. The platelets, CRP, and AST/ALT returned to near normal levels after 12 days. CT, MRI and ultrasound examinations of the painful joints revealed a small amount of fluid in the knee joints, but were otherwise non-specific. We report herein on a case of C. canimorsus sepsis which presented with polyarthritis of the major joints and a multiple pinkish macro-rash, treated adequately with IPM/CS. Early diagnosis and immediate broad-spectrum antibiotics could be the keys to the treatment of severe C. canimorsus infection.