Rat Bite Fever Caused by Streptobacillus moniliformis in a Cirrhotic Patient Initially Presenting with Various Systemic Features Resembling Henoch-Schönlein Purpura.

We herein report the case of a 61-year-old Japanese cirrhotic patient who developed rat bite fever (RBF) and whose first presentation was serious clinical features mimicking those of Henoch-Schönlein purpura (HSP). In addition to the critical clinical conditions, since the histopathology from purpuric skin eruptions was not inconsistent with that of HSP, therapy with prednisolone was promptly started in order to prevent his death. However, initial blood culture on admission yielded a small and slow-growing bacterial growth, which was gradually revealed by further subculture to be a peculiar bacterium, Streptobacillus moniliformis, leading to a definitive diagnosis of RBF. After the immediate cessation of prednisolone, the patient was treated with a more appropriate antibiotic and consequently made a full recovery. An immunocompromised condition with seriously decompensated liver cirrhosis together with moderately severe chronic kidney disease (CKD) in this patient probably exacerbated the severity of the disease.