Background:

Capnocytophaga canimorsus is an oral commensal bacteria in dogs and may cause severe infection following a dog bite. This is a case of fatal C. canimorsus sepsis with acute infectious purpura fulminans (AIPF) in a healthy patient with splenic hypoplasia.
Case presentation:
A healthy 49-year-old man was admitted to the intensive care unit (ICU) for septic shock and AIPF 4 days after a dog bite to his mouth. Computed tomography revealed a small spleen measuring 53 cm3 but no other source of infection. Despite intensive care, the patient died of multiple organ failure and progressive shock on the fifth ICU day. Polymerase chain reaction of blood samples identified the C. canimorsus gene on a later day.
Conclusion:

Capnocytophaga canimorsus from dog bites may cause fatal AIPF. Splenic hypoplasia and bite wounds in well-perfused areas such as the oral cavity are possible risk factors for sepsis. All dog bites should warrant medical attention.