Blastomycosis

Answer 1

Definition

Blastomycosis is a rare infection that may develop when people breathe in (inhale) a fungus called Blastomyces dermatitidis, which is found in wood and soil.

Alternative Names

North American blastomycosis; Gilchrist's disease

Causes, incidence, and risk factors

Blastomycosis occurs in people living in the south-central and midwestern United States and Canada. The infection is seen in 1-2 out of every 100,000 people in areas where the fungus most often occurs. It is even less common outside those areas.

Being around infected soil is the key risk factor.

The disease usually affects people with weakened immune systems, such as those with HIV or who have had an organ transplant. Men are more likely to be affected than women.

Symptoms

Lung infection may produce no symptoms, but when the infection spreads, skin or bone sores (lesions) may appear. The bladder, kidney, prostate, and testes may be affected.

Other symptoms may include:

• Chest pain
• Cough (may produce brown or bloody mucus)
• Fatigue
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Joint stiffnessand pain
• Muscle stiffness and pain
• Rash
• Shortness of breath
• Sweating
• Unintentional weight loss

Signs and tests

• Chest x-ray
• Skin biopsy
• Sputum cultureand examination under the microscope after applying special stains to sputum
• Tissue biopsy

Treatment

Medicines may not be needed for a blastomycosis infection that stays in the lungs, unless it becomes severe. When the disease is severe, or when it spreads outside of the lungs, the following medicines (anti-fungals) may be prescribed:

• Fluconazole
• Itraconazole
• Ketoconazole

Amphotericin B may be used for severe infections.

Follow-up regularly with your doctor to make sure the infection doesn't return.

Expectations (prognosis)

Patients with minor skin sores (lesions) and relatively mild lung infections usually recover completely. If the infection is not treated, it can become severe enough to cause death.

Complications

• Large sores with pus (abscesses)
• Return of the infection (relapse or disease recurrence)
• Side effects from drugs such as amphotericin B

Calling your health care provider

Call your health care 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.

References

Chapman SW. Plastomyces dermatitidis. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 6th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2005: chap 263.

Answer 2

Definition

Blastomycosis is a rare infection that may develop when people breathe in (inhale) a fungus called Blastomyces dermatitidis, which is found in wood and soil.

See also: Skin lesion of blastomycosis

Alternative Names

North American blastomycosis; Gilchrist's disease

Causes, incidence, and risk factors

You can get blastomyocosis by inhaling Blastomyces dermatitidis particles, a fungus that is found in moist soil, particularly where there is rotting vegetation. The fungus enters the body through the lungs, infecting them. The fungus then spreads (disseminates) to other areas of the body. The infection may affect the skin, bones and joints, and other areas.

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

Being around infected soil is the key risk factor. The disease usually affects people with weakened immune systems, such as those with HIV or who have had an organ transplant. 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:

• Bone pain
• Chest pain
• Cough (may produce brown or bloody mucus)
• Fatigue
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Joint pain
• Muscle pain
• Night sweats
• Rash
• Shortness of breath
• Sweating
• Unintentional weight loss

Signs and tests

• Chest CT scan
• Chest x-ray
• Skin biopsy
• Sputum cultureand examination
• Tissue biopsy
• Urine culture

Treatment

Medicines may not be needed for a blastomycosis infection that stays in the lungs, unless it becomes severe. When the disease is severe, or when it spreads outside of the lungs, the following medicines (anti-fungals) may be prescribed:

• Fluconazole
• Itraconazole
• Ketoconazole

Amphotericin B may be used for severe infections.

Follow-up regularly with your doctor to make sure the infection doesn't return.

Expectations (prognosis)

Patients with minor skin sores (lesions) and relatively mild lung infections usually recover completely. If the infection is not treated, it can become severe enough to cause death.

Complications

• Large sores with pus (abscesses)
• Return of the infection (relapse or disease recurrence)
• Side effects from drugs such as amphotericin B

Calling your health care provider

Call your health care 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.

References

Kauffman CA. Blastomycosis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 355.

Reviewed By

Review Date: 09/15/2010

David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.