Clinical Manifestations and Treatment of Blastomycosis.

The causal agents of blastomycosis, Blastomyces dermatitidis and Blastomyces gilchristii, belong to a group of thermally dimorphic fungi that can infect healthy and immunocompromised individuals. Following inhalation of mycelial fragments and spores into the lungs, Blastomyces spp convert into pathogenic yeast and evade host immune defenses to cause pneumonia and disseminated disease. The clinical spectrum of pulmonary blastomycosis is diverse. The diagnosis of blastomycosis requires a high degree of clinical suspicion and involves culture-based and non-culture-based fungal diagnostic tests. The site and severity of infection, and the presence of underlying immunosuppression or pregnancy, influence the selection of antifungal therapy.