Cutaneous blastomycosis: a diagnostic challenge

Primary cutaneous inoculation blastomycosis occurs less commonly than secondary blastomycosis, in which cutaneous lesions most often originate from a primary pulmonary infection which disseminates through the blood or lymphatics to involve the skin. In secondary cutaneous blastomycosis, the primary pulmonary infection is frequently subclinical at the time cutaneous lesions manifest. Here we report two cases that illustrate the difficulty in distinguishing between primary and secondary cutaneous involvement. We also review the expanding literature on blastomycosis since its identification over a century ago.