Blastomycosis: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Blastomycosis?
An infectious disease doctor (a doctor who treats infections) usually leads care for blastomycosis, often with a pulmonologist (a lung doctor) when the lungs are badly affected. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is blastomycosis?
Blastomycosis is an infection. It comes from breathing in spores of a fungus called Blastomyces. The fungus lives in soil and decomposed wood. It lives in parts of the United States. About half of the people who breathe in the spores do not get sick. The other half develop symptoms, which usually start between three weeks and three months later.
Symptoms
Blastomycosis usually affects the lungs. It causes symptoms like those of pneumonia, a lung infection. Symptoms may include:
- Fever.
- Cough and shortness of breath.
- Night sweats.
- Muscle aches or joint pain.
- Chest, rib, or back pain.
- Weight loss.
- Fatigue, which means extreme tiredness.
Some people also develop skin lesions, such as raised bumps, blisters, or ulcers. In severe cases, the infection can spread past the lungs. It can reach the skin, the bones and joints, or the central nervous system, which means the brain and spinal cord. This happens mostly in people with weakened immune systems.
Causes and who gets it
The cause is breathing in spores that the fungus releases, often when soil or rotting wood is stirred up. Some activities stir up soil and raise the risk in areas where the fungus lives. These include forestry work, hunting, fishing, camping, digging, and building or excavation work. High winds can also raise the risk. People with weakened immune systems have the highest risk of severe illness. This includes people with advanced HIV/AIDS, people who have had an organ transplant, and people who are pregnant. It also includes people taking medicines such as corticosteroids or TNF-inhibitors. Risk of infection is higher among certain ethnic groups and among people who do more outdoor activities.
How doctors diagnose it
Doctors may suspect it when pneumonia does not improve with antibiotics. New skin sores after time in an area where the fungus lives are another clue. To test for it, providers collect blood, urine, or tissue samples and send them to a lab. They may also do imaging tests, such as a chest X-ray or a CT scan, which take pictures of the lungs. Results from a blood or urine test are usually available in a few days.
Treatment
Most people who have symptoms need prescription antifungal medicine, drugs that kill fungi. For mild to moderate disease, doctors usually use the antifungal drug itraconazole. For severe disease, doctors usually recommend a drug called amphotericin B. Patients usually take antifungal treatment for six months to one year. The length depends on the person's immune system and how severe the infection is. Providers may check blood levels to make sure the medicine is working.
When to see a doctor
See a provider if you have symptoms of pneumonia after time in an area where the fungus lives, especially if antibiotics do not help. New skin sores after a lung infection are another warning sign. Call 911 or go to the emergency room for trouble breathing. There is no vaccine for blastomycosis.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can order the first tests for a cough or fever that will not go away and can coordinate your care with an infectious disease specialist.
Common questions
Is blastomycosis contagious?
No, it does not spread from person to person. It is caused by breathing in spores from the environment. Pets, especially dogs, can get it too, but spread between animals and people is very rare.
How long does treatment last?
Patients usually take antifungal medicine for six months to one year. The exact length depends on the person's immune system and how severe the infection is.
Can blastomycosis be prevented?
Not completely. There is no vaccine. In areas where the fungus lives, it may not be possible to avoid exposure. Ways to lower risk: stay inside on windy, dusty days. Avoid activities that stir up dirt. Wear long sleeves and pants in the woods.
Who gets very sick from it?
People with weakened immune systems are at highest risk of severe illness. This includes people with advanced HIV/AIDS and people who have had an organ transplant. It also includes people taking medicines such as corticosteroids or TNF-inhibitors.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
