A case of cutaneous Pseudallescheria boydii infection caused by trauma

Abstract

Pseudallescheria boydii is a ubiquitous filamentous fungus. We report a case of cutaneous P. boydii infection of the left knee in a 79-year-old Japanese man who was receiving oral predonisolone (25 mg/day) for radiation pneumonitis after radiation therapy on left breast cancer. He presented with a 2-week-history of a lesion on the left knee. A biopsy specimen from the skin lesion revealed granulomatous inflammation with hyphae. Culture of the pus from the skin specimen confirmed the diagnosis of cutaneous P. boydii infection. rDNA ITS sequence was analyzed to confirm the mycological diagnosis. The patient was treated orally with 200 mg/day of itraconazole. The lesion was gradually cured and left a hypertrophic scar. Cutaneous injury may be responsible for an incidence of localized infection. Such rare fungus infection in immunocompromised patients who have a persistent traumatic skin ulcer needs to be ruled out. An opportunistic infection in immunocompromised patients can be life-threatening and prompt treatment based on accurate diagnosis is important.