A Case of Phaeohyphomycosis Caused by a New Species of Phialophora

A subcutaneous fungus infection that developed in a kidney transplant patient on immunosuppressive maintenance therapy was found to be caused by a new species of Phialophora. This species, P. parasitica, developed in the host's tissues in the form of dematiaceous mycelium. In culture on Sabouraud dextrose agar it is characterized by the formation of phialides that extrude ovoid to ellipsoid phialospores at maturity. The term phaeohyphomycosis is proposed as a collective name for a group of mycoses caused by diverse genera and species of dematiaceous fungi. All the etiologic agents, despite their taxonomic heterogeneity, are characterized and united by the development of dark mycelial elements in the host's tissues. The term 'phaeosporotrichosis,' previously introduced by others for this type of disease, should be discarded on the grounds of inappropriateness.