Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissue caused primarily by dematiaceous (pigmented) fungi. Fonsecaea pedrosoi is the most common etiologic agent, typically introduced through traumatic implantation of contaminated soil or vegetation. The infection presents as verrucous, crusted, or nodular lesions mainly on the lower extremities. Diagnosis is confirmed by identifying characteristic brown, thick-walled, sclerotic bodies ("Medlar bodies") in tissue. Other fungi listed are not associated with chromoblastomycosis but cause different systemic mycoses.

Key clinical point: Fonsecaea pedrosoi is the primary pathogen in chromoblastomycosis, a localized cutaneous mycosis best diagnosed by microscopic examination of skin lesions.

Reference: Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, 9th Edition.