[A 34-year-old woman with cat scratch disease who developed encephalopathy].

We experienced a patient with cat-scratch disease (CSD) who developed encephalopathy. The subject was a 34-year-old female who had been aware of a low-grade fever and swollen inguinal lymph nodes for 1 month. The subject's consciousness became impaired after a headache developed, accompanied by fever, nausea, and vomiting, and she subsequently sought medical consultation. No major abnormalities were observed in the cerebrospinal fluid and cranial magnetic resonance imaging (MRI) was normal. However, necrotizing lymphadenitis was observed on contrast enhanced computed tomography (CT) of the pelvis and granulomatous changes were observed in a surgical lymph node biopsy. As the subject lived with a pet cat, PCR testing for Bartonella henselae (the CSD pathogen) was performed using a tissue biopsy. This was positive and the subject was diagnosed with CSD encephalopathy. There are very few domestic reports of CSD encephalopathy and care must be taken not to overlook this disease.