Fulminant Clostridioides difficile Infection During Repeated High-Dose Cytarabine Consolidation for Acute Myeloid...

Fulminant Clostridioides difficile infection (CDI) is a life-threatening complication during intensive chemotherapy. We report a 69-year-old woman with acute myeloid leukemia who had two CDI episodes of different severity following sequential high-dose cytarabine consolidation cycles. The initial episode was mild diarrhea during myelosuppression and was managed by oral metronidazole. Her diarrhea resolved by day 20, and she was discharged on day 24. She started her second cycle of consolidation 41 days after the first cycle with the same antibiotic prophylaxis. On day 17, she developed watery diarrhea and abdominal pain. Oral metronidazole was started for suspected recurrence. However, she rapidly developed severe metabolic acidosis and septic shock, requiring mechanical ventilation, vasopressors, and continuous hemodiafiltration. Computed tomography showed thickened colonic walls and ascites. The stool PCR was positive for toxin B and negative for hypervirulent strain markers. The aggressive therapy with intravenous metronidazole and nasogastric vancomycin failed, and she died within a few days. The autopsy revealed diffuse pseudomembranous colitis. This case illustrates the unpredictable severity of recurrent CDI during intensive chemotherapy. It highlights the critical importance of guideline-adherent antimicrobial therapy, particularly the use of fidaxomicin or vancomycin rather than metronidazole in high-risk patients.