Endemic Mycoses for Pulmonary Clinicians: From Nodules to ARDS

Endemic fungal infections are increasingly recognized as important causes of community-acquired pneumonia. Despite this, diagnosis is often delayed or misattributed, resulting in significant morbidity and mortality.

Histoplasma capsulatum, Blastomyces species, and Coccidioides species are the most common endemic fungal infections in the United States. These infections share commonalities in modes of transmission and pathogenicity where regional climates, weather patterns, and certain exposures play a key role in infectivity. However, changes in climate and human migration patterns have altered and expanded the traditional maps of endemicity. Antigen- and antibody-based testing have improved diagnostic efficiency but are limited by host immune status. Understanding the proper use and limitations of antigen- and antibody-based testing is key to appropriate diagnosis. We also discuss the management of disseminated infection, recent developments in treatment modalities, and areas of active research.

Our results indicate that a greater number of patients are at risk of endemic fungal infections due to climate change, human migration patterns, and increased use of immunosuppressive medications. Pulmonary manifestations of these infections are similar and typically mild in immunocompetent patients, but clinical presentations can be highly variable, especially in those with disseminated infection. Azole therapy is used for most patients, with liposomal amphotericin B used in the most severe infections.