Blastomycosis

Overview

Blastomycosis is a rare infection caused by a fungus that lives in damp soil, especially in certain parts of North America (like the Mississippi and Ohio River valleys) and in parts of Africa. People usually get it by breathing in tiny dust particles that contain the fungus. It most often affects the lungs, but it can spread to other parts of the body if not treated.

No, blastomycosis is rare. It is sometimes called a 'silent' infection because many people who breathe in the fungus do not get sick.

Anyone can get blastomycosis, but it is more common in adults between 30 and 60 years old. People who live in or travel to areas where the fungus grows, especially those who work or play outdoors in soil, are at higher risk. People with weaker immune systems may develop a more serious form.

Symptoms

Common symptoms

• Cough that does not go away
• Fever and chills
• Chest pain
• Feeling very tired
• Shortness of breath
• Night sweats
• Weight loss without trying

Symptoms in children

• Cough and fever
• Skin sores or bumps that look red or swollen
• Bone pain (if the infection spreads)
• Feeding problems or poor appetite in younger children

Symptoms in older adults

• More severe shortness of breath
• Confusion or drowsiness (signs the infection may be affecting the brain)
• High fever
• More rapid spread to other organs

Causes

Main causes

• Breathing in microscopic spores of the fungus Blastomyces, which grow in moist soil where there are rotting leaves, wood, or organic matter.
• Disturbing soil, like gardening, construction, or digging, can release the fungal spores into the air.

Risk factors

• Living or traveling in areas where Blastomyces is found (especially parts of the US and Canada near the Mississippi and Ohio rivers, and parts of Africa).
• Outdoor activities such as farming, gardening, hiking, or hunting.
• Weakened immune system (from medicines, organ transplant, HIV, or other conditions).
• Being a smoker or having existing lung disease.

When to see a doctor

See a doctor urgently if:

• You have severe symptoms like trouble breathing, coughing up blood, or a very high fever.
• Your symptoms are getting worse, not better, after a few days.
• You have a weakened immune system and any new symptoms.

Book a routine appointment if:

• You have a cough or other lung symptoms that last longer than a few weeks.
• You have a persistent fever, night sweats, or weight loss that you cannot explain.

Diagnosis

Doctors diagnose blastomycosis by asking about your symptoms, travel history, and outdoor activities, then doing tests to look for the fungus in your body. It can look like other lung infections, so lab tests are important.

Tests that may be done

• Sputum culture — checking your phlegm (mucus) for the fungus.
• Blood or urine tests — looking for signs of infection or for the fungus itself.
• Chest X-ray or CT scan — taking images of your lungs to see if there is an infection.
• Biopsy — taking a small tissue sample from your skin, lungs, or another organ to check for the fungus.

What to expect at your appointment

Your doctor may ask you to provide a sample of your phlegm or blood. You might need more than one test to make sure of the diagnosis. If the infection has spread, you may see a pulmonologist (lung doctor) or an infectious disease specialist. Be ready to tell your doctor about any recent travel or outdoor work.

Treatment

Blastomycosis is treated with antifungal medicine. The medicine is usually taken as pills at home, and you may need to take it for several months. In severe cases, medicine may be given through a vein (intravenously) in the hospital first. The exact treatment depends on how serious the infection is and your overall health.

Self-care at home

• Rest as much as you need while your body recovers.
• Drink plenty of fluids to stay hydrated.
• Don't smoke or vape — it can make your lungs worse.
• Follow your doctor's instructions about follow-up visits.

Medical treatments

Antifungal medication is the main treatment. It is usually prescribed for 6 to 12 months, sometimes longer, to make sure the infection is fully cleared. For very severe cases, you may start with intravenous (IV) therapy in the hospital and then switch to pills. Always take the medicine exactly as prescribed, even if you feel better, because stopping early can let the infection come back. Never start or stop any medicine without talking to your doctor.

When is surgery considered?

Surgery is rarely needed. In some cases, if blastomycosis causes a large abscess (a pocket of pus) in the lungs or bones, a doctor may drain it or remove the affected tissue. This is done in addition to antifungal medicine, not instead of it.

Living with this condition

Once you start treatment, you may need to take medicine for many months. It is normal to feel tired, so listen to your body and get plenty of rest. Keep your follow-up appointments so your doctor can check that the infection is clearing. Make sure to finish the entire course of medicine, even if you start to feel better.

Lifestyle tips

• Protect your sleep routine to help your immune system fight the infection.
• Avoid strenuous activities until your doctor says it is safe.
• If you live in an area where the fungus grows, try to avoid stirring up dry soil, or wear an N95 mask if you must dig or garden.
• Tell your doctor about any other health conditions you have.

Diet and exercise

Eating a balanced, healthy diet supports your body during recovery. Drink plenty of fluids. When you feel up to it, light activity like walking can help your energy return, but do not push yourself too hard. Talk to your doctor before starting any new exercise routine.

Mental health and emotional wellbeing

Dealing with a rare long-term infection can be stressful and can sometimes make you feel anxious or down. It is okay to ask for help. Talk to your doctor about how you are feeling, and consider reaching out to a counselor or support group. You don't have to handle it alone.

Prevention

It is not possible to completely prevent blastomycosis, because the fungus is naturally found in soil. If you live in or travel to high-risk areas, you can reduce your chance of breathing in spores by avoiding digging or stirring up soil when possible, wearing a mask if you must do dusty outdoor work, and avoiding activities near piles of damp leaves or wood.

Vaccines

There is no vaccine to prevent blastomycosis.

Screening programmes

Routine screening is not recommended for the general public. Doctors only test for blastomycosis if you have symptoms and a possible history of exposure.

Complications

If left untreated

• The infection can spread from the lungs to other parts of the body, such as the skin, bones, joints, prostate, or brain.
• Serious lung damage, including scarring or cavities.
• Meningitis — swelling of the membranes around the brain and spinal cord, which can be life-threatening.
• In very severe cases, blastomycosis can be fatal if not treated.

Long-term outlook

With proper treatment, most people with blastomycosis recover fully and can return to their normal lives. Treatment takes patience — usually months — but the outlook is very good. Severe cases can be harder to treat, but many people still improve with medicines and care. Your doctor will help guide you through each step.

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