In about 50% of the cases, the disease does not produce any symptoms. In cases, when it does, the following signs are evident in individuals affected with blastomycosis:

• Fever accompanied by chills
• Myalgia
• Cough
• Chest pain 
• Joint pain
• Undue fatigue
• Unexplained weight loss
• Night sweats
• Malaise

When the infection spreads to other body parts and affects the skin [7], then the symptoms include:

• Development of papules that resemble warts or ulcers
• Bleeding from the ulcers
• Nose and mouth are the common areas of occurrence
• The warts are painless and can be grayish to violet in color

Various tests are required to confirm the diagnosis of blastomycosis. One of the best methods to confirm the disease is fungal culture. For this, samples are taken from blood, urine, bone marrow, sputum, liver and skin which are tested for the presence of fungus.

For mild cases of blastomycosis, no treatment may be required if the fungus stays in the dormant state in the lungs. However, if the individuals experience some kind of mild symptoms, then antifungal medications such as intraconazole are recommended.

For more severe cases, a rigorous treatment regime is required. In such cases, treatment with amphotericin B is recommended [8]. In addition, newer generation of antifungal drugs have also been introduced that include voriconazole and posaconazole; but there efficacy in treating blastomycosis is still being tested [9].

Amphotericin B is administered through the intravenous route. Some patients may experience certain side effects with this medicine. Therefore, for individuals who are unable to tolerate deoxycholate formulation of amphotericin B, lipid formulas of voriconazole are given that are well tolerated and are reported to have better CNS penetration [10]. Lipid formulations include flucanozole that is known to be effective against blastomycosis and in cases when the CNS is involved.

The prognosis of the disease is quite favorable with prompt initiation of treatment. Individuals can completely recover from the disease. However, in cases when the treatment is delayed it can even cause death. Immunocompromised patients may have a 29% mortality rate [5].

Complications

Complications arise when the disease is not treated on time and the fungus has attacked other body parts. The following are the various complications of blastomycosis:

• Abscesses characterized by development of large sores with pus
• Infection relapse
• Side effects from drugs used for treating the disease.
• Acute respiratory distress syndrome (ARDS) [6]

The fungus Blastomyces dermatitidis causes blastomycosis. It resides in the soils and rotten woods near lakes and rivers. The fungus is thought to grow like cottony white mold; as its actual growth features has never been observed in the nature.

Blastomycosis is known to peak during the spring and autumn season when the weather is moist and favors optimal growth of the fungus.

The exact incidence of blastomycosis is unknown. However, annual incidence is reported to be 1 in every 100,000 individuals. United States is known to have a large prevalence of blastomycosis. City of Rockford, Ilionis has higher prevalence of blastomycosis with 6.67 cases per 100,000 populations. Although hyperendemic areas like Arkansas, Mississippi, Kentucky and Wesconsin has an incidence rate of up to 40 cases per 100,000 population [1]. There are no significant sex predilection from common source infection data [2]. Blastomycosis occurs in all ages from infancy to the elderly [3].

Blastomyces dermatitidis is a type of dimorphic fungus; wherein the spores of the fungi that get converted to yeast are infectious to humans. The fungus gains entry into the body through the lungs and can stay in the lungs for a prolonged period. It has been estimated that about 50% of individuals affected by this fungus remain asymptomatic. In rest of the cases, the incubation period is about 45 days.

After gaining entry, the fungus multiplies and begins affecting the blood and other organs. Individuals complain of pulmonary problems and in some cases, the disease can also affect the bones, skin and the brain. Immunocompromised host like those suffering with acquired immune-deficiency syndrome (AIDS) are more prone of blastomycosis infection [4].

So far no vaccine has been introduced to provide prevention against blastomycosis. Individuals with weak immune system are more prone to contract the fungus and are advised to avoid going to such areas. However, absolute prevention from the fungus is a bit difficult in the endemic areas. It is thus recommended that individuals take immediate steps to treat infection in order to avoid onset of secondary complications.

Blastomycosis is a fungal infection caused by Blastomyces dermatitidis, a fungus found in wood and moist soil. When individuals breathe in the aerosolized spores of this fungus they develop blastomycosis. The fungus gains entry through the lungs and produces no signs and symptoms if it does not spread to other body parts.

Blastomycosis is more common in inhabitants of Eastern North America, St. Lawrence River Valley, and Central Appalachian Mountains. This condition was first described in the year 1894 by Thomas Casper Gilchrist and hence often referred to as Gilchrist’s disease.

Definition

Blastomycosis is a fungal infection that may cause flu like symptoms in affected individuals. The causative agent in this case is blastomyces dermatitidis. Blastomycosis precipitates as lung infections and if not treated on time can have life threatening complications.

Cause

The fungus known as blastomyces dermatitidis is known to cause blastomycosis. This fungus resides in moist soil and wood. Individuals who inhale the fungus present often with flu like symptoms. 

Symptoms

In many individuals, the fungus stays in inactive state inside the lungs and do not cause any symptoms. In cases when they do, treatment is required to ward off the infection. Symptoms of blastomycosis include fever along with chills, night sweats, fatigue, unexplained weight loss, cough with sputum, chest pain, muscle pain and joint pain.

Diagnosis

Various methods are required for diagnosing the condition. Fungal culture from body fluids is the best way to diagnose blastomycosis. In addition, other tests such as CT scan of the chest, skin biopsy, and chest x-ray along with urine culture are also done. Sputum culture is considered to be one of the best methods to detect the fungus. Diagnosing the condition in children is difficult as they do not produce sputum to be taken for analysis. Therefore, for children invasive procedures need to be performed for arriving at definitive diagnosis.

Treatment

Individuals with mild symptoms require no treatment. Antifungal medications are prescribed for those with moderate to severe symptoms. In severe cases, a rigorous treatment regime is required to clear off the fungus from the body and intravenous administration of amphotericin B is employed. However, certain individuals will exhibit side effects and in such cases lipid formulation of antifungal agents are helpful.

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