Blastomyces dermatitidis

Blastomyces dermatitidis is a dimorphic (two-formed) fungus belonging to the genus Blastomyces.

Depending on the temperature, the fungus appears in two different forms. At temperatures of 25°C, Blastomyces dermatitidis grows as a filamentous mold, and at 37°C it grows in a yeast-like form.

Infection with Blastomyces dermatitidis leads to the so-called blastomycosis, which is particularly widespread in North America.

Clinically, the disease mainly affects the lungs and the skin. In the pulmonary form, symptoms are similar to those of pneumonia, including fever, cough, breathing difficulties, and night sweats, among others. In some affected individuals, especially those with weakened immune systems, blastomycosis can spread to other parts of the body, such as the skin, bones and joints, and central nervous system.

Blastomyces dermatitidis is found in the environment, especially in moist soil and decomposing organic material such as wood and leaves.

Relevance of pathogen in transmission in endoscopy

  • Gastroenterology: Not relevant

  • Pulmonology: High

  • Ear, nose, and throat: High

  • Urology: Not relevant

Relevance for endoscope surveillance

  • Low or moderate concern organism

Transmission route

Blastomyces dermatitidis is transmitted aerogenically, through inhalation of contaminated dust.


Specific resistances have not been described so far.

Sources and further readings

  1. Blastomycosis, Centers for Disease Control and Prevention, Accessed on 07.13.2021.

  2. Gries O, Ly T: Infektologie – Kompendium humanpathogener Infektionskrankheiten und Erreger, Springer-Verlag Berlin Heidelberg 2019.

  3. Miceli A/Krishnamurthy K. Blastomycosis. 2020, Aug 10. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 28723016.

  4. McBride JA et al. Clinical Manifestations and Treatment of Blastomycosis. Clin Chest Med. 2017 Sep;38(3):435–449.