Localized cutaneous infection by Scedosporium prolificans (inflatum)

A 15‐year‐old African‐American man was first seen in July 1992 complaining of a painful growth on the toe of 6 weeks duration. Initial examination revealed a 2‐cm tender verrucous plaque on the dorsal aspect of the right great toe, just distal to the DIP joint. There were focal erosion and underlying granulation tissue. There was no fever or regional lymphadenopathy, and the patient was otherwise healthy and asymptomatic. Initial diagnostic considerations included viral verruca, blastomycosis, Mycobacterium marinum, and (remotely) squamous cell carcinoma. Tissue was submitted for laboratory evaluation, and the lesion was treated empiricaily with liquid nitrogen, Hematoxylin and eosin stained sections showed epidermal acanthosis with underlying granulomatous inflammation. Special stains and cultures for acid‐fast bacteria (AFB) and fungi (on Mycosel agar) were negative. On follow‐up 1 month later, the lesion measured 8 mm; the patient failed to keep further appointments. He returned in July 1993, and examination revealed a well‐circumscribed 3.5 cm ulcerated piaque, extending from the proximal nail I fold to the DIP joint, with minimal surrounding erythema and serosanguinous discharge. Again, the patient was otherwise asymptomatic. Soft tissue radiographs showed no bone or joint involvement. A repeat biopsy showed siminar changes, in addition to extensive dermal necrosis. Cultures for fungus and AFB were again negative. The patient missed and follow‐up appointments until July 1994, At that time, history and examination were essentially unchanged. A third biopsy was submitted for analysis and failed to identify an etiologic agent. Our differential diagnosis included Trichophyton verrucosum, M. marinum, and deep fungal infections. Over the next 2 months, there was no response to empiric trials of minocycline 100 mg po BID, fluconazole 100 mg po qD, or griseofulvin 250 mg po BID. Finally the lesion was excised, and the base curetted and fulgurated. The surgical specimen was submitted for histology and microbiology. Sections stained with hematoxylin and eosin displayed a hyperkeratotic and encrusted proliferation of squamous epithelium without atypia, but with scattered intraepidermal abscesses. The underlying dermis showed extensive fibrovascular proliferation with plasmacytic and lymphocytic Infiltration, similar to the previous biopsies. Special stains did not reveal any visible micro‐organisms. Part of the surgical specimen was plated on inhibitory mold agar (BBL) and brain heart infusion agar (BBL). Four days later colonies appeared in pure culture and were subsequently identified as Scedosporium prolifions (Fig. 1) . The lesion has not recurred after 10 months.