Blastomycosis - Specialists and Information

Blastomycosis is a systemic disease that affects the entire body and not just individual parts.

Experts generally distinguish between:

• North American blastomycosis
• South American blastomycosis, and
• European blastomycosis

All of these diseases are similar, but they are caused by different pathogens. They also have different clinical courses:

• The pathogen responsible for North American blastomycosis is the fungus Blastomyces dermatitidis, which primarily affects the lungs and skin.
• The pathogen responsible for South American blastomycosis is Paracoccidioides brasiliensis. This fungus causes severe skin lesions, including ulcers, which can be fatal.
• Cryptococcus neoformans and Cryptococcus bacillisporus are the pathogens responsible for European blastomycosis.

Blastomycosis is an infection caused by inhaling the spores of the fungus Blastomyces dermatitidis @ Dr_Microbe /AdobeStock

Blastomycosis is a rare disease that occurs only in limited areas (endemic). In endemic areas, there are one to two cases of blastomycosis per 100,000 inhabitants per year.

Men and women are affected by North American blastomycosis with equal frequency.

South American blastomycosis occurs primarily in men aged 30 and older. Older adults, children, and women are rarely affected. About one-quarter of those affected die from South American blastomycosis.

The European form of blastomycosis is very rare. Europe is not one of the pathogen’s main areas of distribution.

Blastomycosis occurs primarily in North and South America. However, it also occurs in countries such as South Africa, Tanzania, India, Israel, and Saudi Arabia. North American blastomycosis occurs primarily in the southern United States and southern Canada.

The areas around the Mississippi River and the Great Lakes, such as Lake Michigan, are particularly affected. In these areas, animals such as dogs are primarily affected by the disease. Transmission from animals to humans is not possible.

Blastomycosis in South America occurs mainly in Brazil. Endemic areas are regions with a warm climate and high humidity, as the fungi can spread particularly well there.

You can contract blastomycosis if you come into contact with the fungal spores. Infection usually occurs when you inhale dust or small soil particles containing the fungal spores. Transmission from person to person or from animals to humans never occurs.

You can become infected if you have cuts or abrasions on your hands or feet and come into contact with contaminated soil. Fungal spores carrying blastomycosis can enter the body through breaks in the skin and cause the disease.

Once inside, they multiply and spread. The incubation period varies widely; the first symptoms usually appear after one and a half months.

The fungal spores primarily attack lung tissue and the skin. If the spores spread to the lungs of the affected person, pneumonia with fever develops. In cases of blastomycosis involving the lungs, symptoms usually include coughing and shortness of breath, as well as flu- or tuberculosis-like symptoms.

In severe cases, the infection can also affect the bones.

Experts generally distinguish between the pulmonary and cutaneous forms of the disease based on the symptoms. 

Pulmonary blastomycosis causes the symptoms described above. In cutaneous blastomycosis, symptoms primarily manifest on the skin, leading to skin discoloration and the formation of ulcers.

Blastomycosis usually manifests primarily in the lungs or on the skin @ Dr_Microbe /AdobeStock

In general, various nonspecific symptoms may occur in the context of blastomycosis. 

These include:

• Fever
• Chills
• Muscle pain
• Headaches
• Hoarseness 
• Pain when urinating
• Night sweats
• Weight loss

Blastomycosis is a severe, systemic disease. This means that the entire body is affected by the fungal infection. If doctors can quickly make the correct diagnosis and initiate treatment, blastomycosis is usually highly treatable. 

However, since people in rural areas of Latin America are particularly affected, the lack of healthcare leads to severe cases. 

The causative fungus spreads throughout the body, damaging internal organs, bones, and the nervous system.

Severe cases of blastomycosis often lead to death. However, if blastomycosis is treated correctly, it is very likely that the patient will recover.

Since blastomycosis is a potentially fatal disease, a rapid diagnosis is very important. Only then can targeted treatment be administered. 

To diagnose blastomycosis, the doctor first takes a detailed medical history. This is important to determine which symptoms the patient is experiencing and how long they have persisted. The consultation helps the doctor determine whether the condition is indeed blastomycosis.

The doctor then performs a physical examination. Since blastomycosis is often associated with lung involvement, the doctor auscultates the patient’s lungs. 

In cases of pulmonary blastomycosis, the doctor may detect abnormal breathing sounds, which can also occur with pneumonia.

In cases of cutaneous blastomycosis, the doctor will find skin lesions, primarily on the extremities and the face. These lesions may be ulcers or warts. In severe cases, the doctor may also detect damage to the patient’s bones or joints.

In men, inflammation of the prostate may occur as a result of blastomycosis. 

Following the physical examination, the doctor may already make a preliminary diagnosis, which must be confirmed by further tests.

The doctor will not make a definitive diagnosis until a microscopic saliva or skin test comes back positive for blastomycosis. In this case, the fungal cells are visible under the microscope.

• How can you recognize blastomycosis on your own?

Since blastomycosis is an extremely rare disease associated with nonspecific symptoms, self-diagnosis is very difficult. 

If you suspect you have blastomycosis based on your symptoms, you should inform your doctor of this suspicion. However, you should leave the final diagnosis to a specialist.

• Differential Diagnosis for Blastomycosis

The symptoms of blastomycosis also occur in many other diseases (pneumonia, flu-like infections, skin diseases, other fungal infections). It is therefore necessary to identify the pathogen.

Treatment for blastomycosis should begin immediately after diagnosis. Otherwise, there is a risk that the spores will spread throughout the body and lead to sepsis with multiple organ failure. 

This complication is usually untreatable and leads to death. In rare cases, doctors must surgically remove ulcers and lesions.

• Topical Therapy

Since blastomycosis affects the entire body, local therapy is not effective.

• Systemic therapy

If a patient is diagnosed with blastomycosis, the treating physician prescribes an antifungal medication. This is a drug that combats fungal infections. 

Medications such as itraconazole or amphotericin B are most commonly used. Drug therapy for blastomycosis must be administered over an extended period. A treatment period of three to six months is generally recommended. It is particularly important to note that the patient must continue taking the medication even after all symptoms have resolved.

There are no specific measures that can help prevent blastomycosis. To date, there are also no vaccines or prophylactic medications available. Nevertheless, there are some precautions you can take to reduce your risk.

1. Tip:

Research endemic areas thoroughly before traveling abroad: Before traveling to high-risk areas, you should learn as much as possible about the affected regions. This is especially important if you are traveling to rural areas of South America. If you are aware of the risks before you travel, you can reduce your exposure by taking safety precautions.

1. Tip:

Ensure adequate protection in endemic areas: If you are in an endemic area, it is advisable to take certain protective measures. For example, if you have cuts or scrapes on your hands, avoid working with soil that may be contaminated. In this case, you should wear protective clothing and a respirator.

1. Tip:

Educate yourself about this disease: Learn everything you can about blastomycosis. This knowledge will help you protect yourself and take the right steps quickly if you become ill.

Blastomycosis is a serious disease. If left untreated, it often leads to death. With a correct diagnosis and the initiation of antifungal therapy, blastomycosis is highly treatable.