This diverse group of fungal infections are caused by dematiaceous fungi. There are four main clinical presentations of the disease with overlap within some of the categories. The cutaneous lesions may present as solitary nodules, cysts, or verrucous proliferations. Infections often result from implantation of an infected splinter or other trauma.
Immunocompromised patients are also at risk.
Homonema dematioides Bipolaris spicifera Phoma sp. Homonema dematioides Bipolaris spicifera Phoma sp. Cladosporium trichoides Exserohilum sp. Under the microscope, there is a circumscribed cyst or abscess in the lower dermis or subcutis. It is walled off with dense fibrous tissue infiltrated by chronic inflammatory cells with scattered giant cells.