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Definition

Blastomycosis is an infection caused by breathing in the Blastomyces dermatitidis fungus. The fungus is found in decaying wood and soil.

Alternative Names

North American blastomycosis; Gilchrist disease

Causes

You can get blastomycosis by contact with moist soil, most commonly where there is rotting wood and leaves. The fungus enters the body through the lungs, where the infection starts. The fungus can then spread to other parts of the body. The disease may affect the skin, bones and joints, and other areas.

Blastomycosis is rare. It is found in the central and southeastern United States, and in Canada, India, Israel, Saudi Arabia, and Africa.

The key risk factor for the disease is contact with infected soil. It most often affects people with weakened immune systems, such as those with HIV/AIDS or who have had an organ transplant, but it can also infect healthy people. Men are more likely to be affected than women.

Symptoms

Lung infection may not cause any symptoms. Symptoms may be seen if the infection spreads. Symptoms may include:

Most people develop skin symptoms when the infection spreads. You may get papules, pustules, or nodules on exposed body areas.

The pustules:

  • May look like warts or ulcers
  • Are usually painless
  • Vary in color from gray to violet
  • May appear in the nose and mouth
  • Bleed easily and form ulcers

Exams and Tests

The health care provider will perform a physical examination. You'll be asked about your medical history and symptoms.

If the provider suspects you have a fungal infection, diagnosis can be confirmed by these tests:

Treatment

You may not need to take medicine for a mild blastomycosis infection that stays in the lungs. The provider may recommend the following antifungal medicines when the disease is severe or spreads outside of the lungs.

  • Fluconazole
  • Itraconazole
  • Ketoconazole

Amphotericin B may be used for severe infections.

Follow up regularly with your provider to make sure the infection does not return.

Outlook (Prognosis)

People with minor skin sores (lesions) and mild lung infections usually recover completely. The infection can lead to death if not treated.

Possible Complications

Complications of blastomycosis may include:

  • Large sores with pus (abscesses)
  • Skin sores can lead to scarring and loss of skin color (pigment)
  • Return of the infection (relapse or disease recurrence)
  • Side effects from drugs such as amphotericin B

When to Contact a Medical Professional

Contact your provider if you have symptoms of blastomycosis.

Prevention

Avoiding travel to areas where the infection is known to occur may help prevent exposure to the fungus, but this may not always be possible.

Gallery

Coronavirus
Coronaviruses are a family of viruses. Infection with these viruses can cause mild to moderate respiratory illnesses such as the common cold. Some coronaviruses may cause severe illness and lead to pneumonia or even death.
Sputum test
A sputum sample is obtained by coughing deeply and expelling the material that comes from the lungs into a specimen container. The sample is transferred to a slide and examined under a microscope. A positive result indicates a fungal infection in the lungs.
Lung biopsy
A needle lung biopsy is performed when there is an abnormal condition that is near the surface of the lung, in the tissues surrounding the lungs, or on the chest wall. The test can be performed to obtain a sample for culture when infection of the lung is suspected, and sputum or bronchoalveolar lavage cultures have not identified the cause of the infection.
Osteomyelitis
Osteomyelitis is infection in the bones. Often, the original site of infection is elsewhere in the body, and spreads to the bone by the blood. Bacteria or fungus may sometimes be responsible for osteomyelitis.

References

Elewski BE, Hughey LC, Hunt KM, Hay RJ. Fungal diseases. In: Bolognia JL, Schaffer JV, Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2018:chap 77.

Gauthier GM, Klein BS. Blastomycosis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 264.

Kauffman CA, Galagiani JN, Thompson GR. Endemic mycoses. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 316.

Last reviewed September 10, 2022 by Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team..

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