Diagnosis: Blastomycosis
Nodular skin lesions of blastomycosis, one of which is a bullous lesion on top of a nodule. From the CDC library.
Nodular skin lesions of blastomycosis, one of which is a bullous lesion on top of a nodule. From the CDC library.
Submitted by dermRounds Dermatology Network. Originally posted February 6, 2009.
See case discussion.
• Squamous cell carcinoma • Pyoderma gangrenosum • Tuberculosis (cutaneous) • Bromoderma/iododerma • Keratoacanthoma • Sporotrichosis • Nocardiosis
• Caused by Blastomyces dermatitidis — dimorphic fungus endemic to Great Lakes, Ohio/Mississippi River valleys • Cutaneous lesions: verrucous, crusted plaques with violaceous borders — can mimic SCC • Pulmonary involvement is primary; skin is most common extrapulmonary site • Broad-based budding yeast on histology/cytology — pathognomonic • Unlike histoplasmosis, blastomycosis is NOT typically an opportunistic infection in HIV • Culture on SDA at 25°C (mold) and 37°C (yeast) — definitive diagnosis
Tags: blastomycosis, dermrounds dermatology network