How do I know if I have Blastomycosis?

Blastomycosis is a fungal infection caused by inhaling spores of Blastomyces dermatitidis, typically found in moist soil and decaying organic matter. You should suspect Blastomycosis if you develop persistent, flu-like respiratory symptoms—such as a cough, fever, or chest pain—after spending time in endemic regions, particularly the Ohio and Mississippi River valleys or the Great Lakes area.

What are the early signs of Blastomycosis?

Because Blastomycosis often mimics bacterial pneumonia or even lung cancer, it can be difficult to identify. Early symptoms generally appear 3 to 15 weeks after exposure. Patients often report a dry, non-productive cough, night sweats, fatigue, and unexplained weight loss. In some cases, Blastomycosis can spread to the skin, causing painless, wart-like lesions or ulcers, which are highly specific indicators that warrant immediate clinical attention.

How is Blastomycosis diagnosed?

Diagnosis requires a high index of suspicion, especially if you live in or have traveled to areas where Blastomycosis is endemic. If you are concerned, you should ask your physician for the following diagnostic tests:

• Sputum or Tissue Culture: The "gold standard" for identifying the fungus.


• Antigen Testing: A urine or serum test that provides rapid results for Blastomycosis.


• Microscopic Examination: A biopsy or fluid sample to look for the characteristic broad-based budding yeast cells.


• Chest X-ray or CT Scan: To visualize lung infiltrates or masses associated with the infection.

When is Blastomycosis a medical emergency?

Seek urgent care if you experience severe shortness of breath, high fever, coughing up blood, or confusion. In rare instances, Blastomycosis can disseminate to the central nervous system or bones, causing neurological deficits or severe bone pain. If you have been treated for "pneumonia" with antibiotics but your symptoms have not improved after 7–10 days, return to your provider and specifically ask: "Could this be a fungal infection like Blastomycosis?"

Next steps

• Consult an infectious disease specialist if your primary care provider is unfamiliar with fungal infections.


• Share your travel history or recent outdoor activities (gardening, hunting, or construction) with your doctor.


• Join our community at DiseaseMaps.org to connect with 27 other members who have navigated a Blastomycosis diagnosis.

Medical Disclaimer: This content is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases (GARD) Information Center: Blastomycosis.


• CDC: Fungal Diseases - Blastomycosis Clinical Information.


• Orphanet: Rare Disease Database.