Chromoblastomycosis Caused by Phialophora richardsiae

Chromoblastomycosis is a chronic fungal disease of the skin and subcutaneous tissues caused by a group of dematiaceous (black) fungi. The most common etiologic agents are Fonsecaea pedrosoi and Cladophialophora carrionii, both of which can be isolated from plant debris. The infection usually follows traumatic inoculation by a penetrating thorn or splinter wound. Several months after the injury, painless papules or nodules appear on the affected area; these papules then progress to scaly and verrucose plaques. We report a case of chromoblastomycosis caused by Phialophora richardsiae, which has been rarely associated with chromoblastomycosis. The case involved a 43-year-old male, who for the past 2 months had noted an erythematous, pustulous plaque that was somewhat dark brown in color on his right shin; the plaque also had intermittent purulent discharge and crust formation. On histopathological examination, chronic granulomatous inflammation and sclerotic cells were seen. The tissue fungus culture grew out the typical black fungi of P. richardsiae, which was confirmed by polymerase chain reaction. The patient has been treated with a combination of terbinafine and itraconazole for 3 months with a good clinical response.