Blastomycosis: A case report and review of the literature

Background Blastomycosis is a chronic granulomatous and suppurative mycosis caused by the fungus Blastomyces dermatitidis. This is a dimorphic fungus, which exists as a non-pathogenic mold in mycelial form in nature and converts to pathogenic yeast at body temperature. Infection is acquired by either inhalation or inoculation. We report a case of blastomycosis with severe involvement of the scalp, face, and neck, with no evidence of systemic involvement. Methods Biopsy specimen was stained with hematoxylin and eosin, periodic acid-Schiff (PAS), PAS with diastase digestion, and Grocott. Culture was performed on a Sabouraud's dextrose agar plate using an aseptic technique as per standard operating procedure for processing mycology specimens at our institution. A lactophenol cotton blue preparation from the cultured material was performed. Results Histopathologic examination showed pseudoepitheliomatous hyperplasia and a granulomatous inflammation with round to oval organisms, with refractile cell walls in the cytoplasm of giant cells. PAS, PAS with diastase digestion, and Grocott stains enhanced the organisms. Cultured material showed growth after 10days, and the lactophenol cotton blue preparation from the cultured material showed the organism to be Blastomyces dermatitidis. Sensitivity studies favored treatment with itraconazole. Radiological examination of the patient showed no evidence of systemic involvement. Conclusions Our case may represent the rare primary cutaneous inoculation blastomycosis as lesions started on an area of previous trauma. Treatment with itraconazole was successful.