Abstract: A 39-year-old man was found to have reduced blood cells during physical examination 8 years ago. Cyclosporine and prednisone were taken for a long time, after undergoing bone marrow, flow cytometry and other examinations to diagnose paroxysmal nocturnal hemoglobinuria (PNH). More than 2 months ago,his left lower extremity was scratched, accompanied by ulceration, redness, swelling and pain. Recently he had been admitted to the hospital and immune indicators were reduced, accompanying by secondary hyperglycemia. Wound tissues and secretions were taken for pathological examination and pathogenic testing. Piperacillin/tazobactam was used for empirical anti-infective therapy. After being diagnosed with Prototheca wickerhamii infection, the antibiotic was replaced by amphotericin B according to antimicrobial susceptibility testing. The dosage of the 1st day was 1 mg, the 2nd to 4th days were 10mg and 5th-10th days were 25 mg once a day. Due to elevated creatinine,the dosage was reduced to 15 mg every other day and wound care was performed at the same time. At last, there was no obvious inflammatory secretion and the wound had healed, when re-examining one month later.

Key words: paroxysmal nocturnal hemoglobinuria(PNH), Prototheca wickerhamii, soft tissue infections, amphotericin B