Waterhouse-Friderichsen syndrome secondary to Capnocytophaga canimorsus septicemia and demonstration of bacteremia by peripheral blood smear.

Waterhouse-Friderichsen syndrome caused by Capnocytophaga canimorsus septicemia was fatal in a previously healthy 47-year-old woman. The patient died suddenly in less than 12 hours after presentation, in spite of supportive measures, including ventilation, antibiotic coverage, pressor therapy, and multiple transfusions of blood products. The diagnosis of infection due to an unusual organism was suspected earlier in the course of management after review of the peripheral blood smear. The importance of the findings in the blood smear and their correlation with infection due to this organism are discussed.