[Prolonged fever and monocytosis after hemorrhoidectomy and treatment with methotrexate--listeriosis with cerebral abscess].

HISTORY AND CLINICAL FINDINGS: A 58-year-old man was admitted because of septic fever for about one week with onset two weeks after an hemorrhoidectomy. He had been receiving methotrexate (MTX) since boyhood for severe psoriasis. Fifteen years before he had undergone a splenectomy after abdominal trauma. The patient was found to have diminished cognitive functions and memory disturbance, but no focal neurological deficits.

INVESTIGATIONS: Laboratory tests were negative for inflammatory disease (normal white blood cell count, CRP and procalcitonin) and serial blood cultures remained sterile. Cranial computed tomography (CCT), done because viral encephalitis was suspected, revealed a large focus in the left hemisphere, further identified as abscess on magnetic imaging.

TREATMENT AND COURSE: The patient's fever subsided within two days of treatment with ampicillin and ciprofloxacin. The patient was sent to the department of neurosurgery for further diagnosis. Stereotactic biopsy revealed Listeria monocytogenes. Antibiotic treatment was modified in accordance with the microbiological results and the patient was transferred to a rehabilitation unit.

CONCLUSIONS

Lack of pathological levels of CRP, procalcitonin and white blood cell count does not exclude cerebral abscess in a patient with prolonged fever and without marked neurological deficits. Preceding treatment with immunosuppressive drugs, especially MTX, and failing response to cephalosporins should lead to consideration of listeriosis in the differential diagnosis.