A case of blastomycosis-like pyoderma caused by mixed infection of Staphylococcus epidermidis and Trichophyton rubrum

Blastomycosis-like pyoderma (BLP) is a type of chronic pyoderma characterized histologically by specific epidermal changes namely: pseudoepitheliomatous hyperplasia and intraepithelial abscesses. These epidermal changes are also seen in blastomycosis (referred to as deep dermatophytosis in North America). Here, we describe the case of a 53-year-old male with prurigo nodularis, diabetes, and chronic lymphocytic leukemia who presented with multiple yellowish-red colored papules that coalesced to form a vegetating plaque. In addition to the typical features of BLP, spores with budding were seen histopathologically in a biopsy specimen. Cultures of a skin specimen grew Staphylococcus epidermidis and Trichophyton rubrum. Antibiotic therapy was effective but failed to eliminate the lesion until antifungal therapy using terbinafine was administered concurrently. Past reports suggest that BLP is mainly caused by bacterial infection, but our case suggests that fungal infection can also be involved as the causative organism in BLP.