Invasive phaeohyphomycosis due to Parathyridaria percutanea in a liver transplant recipient.

backgroundParathyridaria percutanea is a rare melanized fungus causing subcutaneous phaeohyphomycosis, previously reported only in renal transplant recipients. We report the first fatal case in a liver transplant (LT) recipient. CASE PRESENTATION: A 58-year-old Somali woman developed a right foot fungating mass 10 months post-LT during intensive immunosuppression for multiple episodes of T-cell-mediated and antibody-mediated rejection (high-dose corticosteroids, antithymocyte globulin, plasmapheresis). Cultures of drainage and subsequent operative deep-tissue cultures grew Enterococcus faecalis and Finegoldia species, together with a non-sporulating filamentous mould. Despite empiric antifungals, infection progressed proximally in sporotrichoid pattern. Molecular identification using DNA sequencing of ITS and D1/D2 regions identified P. percutanea after three weeks. Treatment with liposomal amphotericin B/voriconazole was complicated by acute kidney injury requiring amphotericin discontinuation. Despite antifungal therapy and surgical debridement, the patient developed progressive encephalopathy and allograft dysfunction, resulting in death.

conclusionsThis first fatal P. percutanea infection following LT highlights the importance of early molecular diagnostics for non-sporulating filamentous fungi in immunocompromised hosts and management challenges under intensive immunosuppression. CLINICAL TRIAL NUMBER: Not applicable.