What are the other Names for this Condition? (Also known as/Synonyms)

• Chicago Disease
• Gilchrist’s Disease
• North American Blastomycosis

What is Blastomycosis? (Definition/Background Information)

• Blastomycosis is a rare, systemic, and serious fungal infection caused by breathing in a fungus called Blastomyces dermatitidis, which is found in wood and soil
• The fungus enters through the lungs and spreads to other parts of the body and may affect the skin, bones, joints, and other organs. Individuals with weak immune systems are more at risk for widespread disease
• If Blastomycosis only affects the lungs and the infection is mild, typically no pulmonary symptoms are present. Symptoms are usually manifested when the infection spreads to other body organs
• Generally, mild infection that is limited to the lungs requires no treatment. Anti-fungal medications are the treatment of choice in the case of disseminated infection. With appropriate treatment, Blastomycosis has a good prognosis

Who gets Blastomycosis? (Age and Sex Distribution)

• Individuals of all ages may be affected by Blastomycosis
• Both genders are affected, but men are affected more commonly than women

The fungus is limited in its geographical dispersion. Blastomycosis is observed in the following regions of the world:

• South-Eastern United States
• Canada
• India
• Israel
• Saudi Arabia
• Africa

The distribution levels of Blastomyces dermatitidis are higher in certain parts of United States and Canada.

What are the Risk Factors for Blastomycosis? (Predisposing Factors)

The risk factors for Blastomycosis include:

• Contact with infected soil: Any individual who comes in close contact with infected soil is at risk  of being infected by the fungus
• Weak immune system: Immunocompromised individuals, (such as AIDS patients), individuals with organ transplant, and those on immunosuppressive therapies (for cancer or other conditions) are at higher risk of contracting Blastomycosis

People who are outdoors and exposed to disrupted soil in endemic areas of Blastomycosis are at highest risk:

• Outdoor workers such as earthmoving operators
• Farmers
• Hunters
• Animal care workers

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Blastomycosis? (Etiology)

• Blastomycosis is a systemic fungal infection caused by the fungus Blastomyces dermatitidis that is found in wood and soil
• The fungus enters into the lungs through inhalation and spreads to other parts of the body. It may affect the skin, bones, joints, and other areas
• The Blastomycosis organisms can be implanted directly into the skin. This is most frequently seen in animal care workers with exposure to infected animals, either by needle stick injury or via bites

What are the Signs and Symptoms of Blastomycosis?

Since the infection usually begins in the lungs, various signs and symptoms of pulmonary Blastomycosis are exhibited. These may include:

• Acute pneumonia
• Acute respiratory distress syndrome (ARDS)
• Chronic pneumonia
• Presence of a lung mass

When lung signs and symptoms are mild, the diagnosis is mainly made after infection spread to sites outside the lungs. When it spreads to other body organs, the following signs and symptoms are manifested:

• Pain in the bones and joints; pain in the muscles
• Chest pain and cough
• Fever and night sweats
• General feeling of illness and uneasiness
• Fatigue
• Considerable weight loss
• Appearance of papules, pustules, and nodules on the exposed areas of skin
• Skin scarring, loss of pigment in the affected skin areas
• Central nervous system signs such as headaches, seizures, etc.

How is Blastomycosis Diagnosed?

The diagnosis of Blastomycosis includes a thorough physical exam along with evaluation of medical history. The diagnostic tests for Blastomycosis may include:

• Culture of sputum and urine
• KOH microscopic testing of pus from an affected site can show the typical yeast forms
• PCR testing of urine or sputum
• X-ray and CT scan of the chest
• Skeletal survey: X-Rays of multiple long bones to evaluate for infection of the bone
• Skin biopsy or biopsy of the affected organ: A small sample of the affected organ is taken and sent to a pathology laboratory for examination under a microscope
• Culture of skin biopsy tissue

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Blastomycosis?

The complications of Blastomycosis could include:

• Abscess: The skin may be filled with sores that discharge pus
• Relapse or recurrence of the infection: When left unattended or if treatment is not provided, the likelihood of disease recurrence is high
• Complications associated with non-skin sites, such as joints, bone, and central nervous system, which can be severe

How is Blastomycosis Treated?

The treatment measures for Blastomycosis may include:

• If the infection is mild and limited to the lungs, oral antifungal medications will be given
• When infection spreads to other areas of the body, anti-fungal medications may be prescribed by the physician that include Fluconazole, Itraconazole
• Some strains of Blastomycosis are resistant to itraconazole
• Severe infections or those with a poor response to oral antifungals may be treated with Amphotericin B
• In areas of skin scarring from the lesions, surgical excision can remove residual disease which might serve as a focus of recurrence

In order to prevent relapse of the infection, regular follow-up with the healthcare provider is required.

How can Blastomycosis be Prevented?

• Avoiding travel to local (endemic) areas where Blastomycosis prevalence is observed to be generally high can help prevent infection
• Individuals in the endemic areas (and travelers to the endemic regions) who are prone to infection from soil and wood, should take adequate measures to minimize the risk

What is the Prognosis of Blastomycosis? (Outcomes/Resolutions)

• Individuals with minor lung infection and minor skin lesions can recover completely with proper and immediate treatment
• Blastomycosis disease can be fatal if left unattended, especially in immunocompromised individuals

Additional and Relevant Useful Information for Blastomycosis:

Skin lesions in Blastomycosis may look like a wart, a skin cancer, or an ulcer; hence, people living in the endemic areas should consult a physician if they notice any suspicious skin lesions.