Blastomycosis

What is blastomycosis?

Blastomycosis is an illness you get from breathing in the fungus Blastomyces. It can cause flu-like symptoms and sometimes spreads from your lungs to other parts of your body.

Blastomyces lives in dirt or rotting wood, usually in areas near water, and you can breathe it in if you disturb the ground. Unlike the umbrella-like mushrooms that pop up in the soil, Blastomyces is a type of fungus that’s too small to see.

Blastomycosis used to be called Gilchrist disease or Chicago disease.

What are the symptoms of blastomycosis?

Symptoms of blastomycosis include:

• Fever.
• Chills.
• Fatigue.
• Cough.
• Shortness of breath (dyspnea).
• Muscle aches.
• Coughing up blood.
• Night sweats.
• Skin sores, ulcers, bumps or blisters.

About half of all people with blastomycosis don’t have any symptoms.

What does Blastomyces dermatitidis look like?

Blastomyces dermatitidis is a type of blastomycosis that can spread to your skin. It can look like large bumps, warts or sores. They might be large, open wounds or closed clusters of bumps. They’re often scabbed or crusted over.

What causes blastomycosis?

Many types of the fungus Blastomyces cause blastomycosis. But you’re most likely to get sick from Blastomyces dermatitidis (B. dermatitidis).

Blastomyces likes to live near water — particularly in or along riverbeds. It’s found in many parts of the world, but it’s most common in parts of North America, especially in areas around the Ohio and Mississippi Rivers, the Great Lakes and the Saint Lawrence River. This includes:

• Midwestern U.S. states. There are hotspots — where blastomycosis is more common — in Wisconsin and Minnesota.
• South Central and Southeast U.S. states.
• Southeastern Canada. This includes Ontario, Quebec, Manitoba and Saskatchewan.

There have also been cases of blastomycosis in the U.S. Northeast.

How do you get blastomycosis?

You get blastomycosis from breathing in Blastomyces mold from moist soil or rotting wood. It can grow in your lungs and sometimes spread to other parts of your body through your blood. Outbreaks sometimes happen when large areas of soil are disturbed by construction or excavation activity.

Blastomycosis isn’t contagious (it doesn’t spread from person to person).

Who’s at risk for blastomycosis?

Anyone who lives in or travels to areas where Blastomyces is found is at risk for blastomycosis. But you might be at a higher risk if your job or hobbies involve disrupting soil or spending time near lakes or rivers. These might include:

• Construction.
• Hunting.
• Fishing.
• Camping.
• Hiking.

Very rarely, veterinarians have gotten blastomycosis from a contaminated needle. This can happen when treating an animal with blastomycosis.

You’re more at risk for severe illness with blastomycosis if you:

• Have a weakened immune system. HIV and immunosuppressive medications are common causes of a weakened immune system.
• Have COPD (chronic obstructive pulmonary disease) or other chronic lung conditions.
• Are older than 50.

What are the complications of blastomycosis?

The main complications of blastomycosis include acute respiratory distress syndrome (ARDS) and the fungus spreading to other parts of your body. From your lungs, it can move into your bloodstream and spread to other organs, including your:

• Skin.
• Bones.
• Central nervous system (brain and spinal cord).

How is blastomycosis diagnosed?

To diagnose blastomycosis, a healthcare provider might take a sample of your blood, pee (urine) or sputum (mucus coughed up from your lungs). If you have skin ulcers, they might also take a sample of tissue (biopsy) from an ulcer.

They’ll send the sample to a lab to:

• Try to grow (culture) Blastomyces. This is the best way to diagnose blastomycosis. But this can take a long time — several weeks — and your provider might want to treat you before results are available.
• Look for Blastomyces yeast. PCR technology can help identify Blastomyces DNA in a sample of tissue or body fluid.
• Test for signs of Blastomyces (antigens or antibodies)in your body.

They might also use chest X-rays or CT scans (computed tomography scans) to look at the inside of your lungs.

How can you tell if you have blastomycosis?

Blastomycosis can look similar to other diseases, including pneumonia. You might suspect you have blastomycosis if you’ve completed antibiotic treatment and you’re still sick. Let your provider know if you live near or have traveled to areas where Blastomyces lives, or if your job or hobbies involve working with or disturbing soil.

How is blastomycosis treated?

Providers treat blastomycosis with antifungal treatments, including amphotericin B (amB) and itraconazole. In some cases, they might also give you corticosteroids to reduce inflammation.

Can I prevent blastomycosis?

It’s hard to avoid breathing in Blastomyces fungus if you live in an area where it’s common. While not entirely preventable, there are some steps you can take to reduce your risk of blastomycosis:

• Avoid disturbing large areas of dirt and dust, especially in areas near water.
• If your job or hobbies expose you to soil that’s likely to contain Blastomyces, wear an N95 (or KN95) respirator mask to help filter the air you breathe.

What can I expect if I have blastomycosis?

Blastomycosis doesn’t go away on its own. You’ll need to take antifungal medication for several weeks. You might need treatment for a year or longer if:

• You’re severely ill.
• The fungus has spread beyond your lungs.
• You have chronic lung disease.
• You have a compromised immune system.

What is the survival rate of blastomycosis?

The survival rate for blastomycosis in most people is over 90%. Chronic lung conditions and diseases that compromise your immune system can put you at a higher risk for life-threatening illness.

When should I see my healthcare provider?

See a healthcare provider if you have flu-like symptoms, cough or shortness of breath that aren’t getting better after a week, or are getting increasingly worse over time. Tell your provider if your job or hobbies might expose you to the fungus that causes blastomycosis or if you’ve traveled to an area where the fungus is found.

When should I go to the ER?

Go to the emergency room if you have symptoms of serious illness, including:

• High fever (over 103 degrees Fahrenheit/40 degrees Celsius).
• Severe or sudden shortness of breath.
• Chest pain.
• Coughing up blood.
• Confusion or other mental changes.
• Seizures.
• Blue skin, lips or nails (cyanosis).

What questions should I ask my doctor?

It might be helpful to ask a provider:

• Am I at high risk for severe blastomycosis?
• Are there any special precautions I should take to reduce my risk of blastomycosis?
• How do I take my medications?
• What signs of serious illness should I look out for?

Can Blastomyces be in a house?

It’s unlikely that you’d find Blastomyces in your house, except in dirt brought in on clothing. The fungus grows on rotting wood and moist soil, so it wouldn’t survive on your clothes after you wash them.