Histoplasmosis

Histoplasmosis occurs in many areas of the world. The fungus is found in soil that is contaminated with bird or bat droppings. It usually gets into the body when it is inhaled into the lungs. Most of the time, the infection stays in the lungs and causes respiratory problems. If the infection travels to other body organs, it is known as disseminated histoplasmosis.

Some infected people have no symptoms. Some people with histoplasmosis have a cough. Other symptoms can include the following:

• chest pain
• fever
• malaise, or a vague feeling of illness

Disseminated histoplasmosis can cause symptoms in other body organs. Some people may have swollen lymph nodes. Others have changes in behavior, as well as cognitive impairments.

In a geographic area where the fungus is common, up to 80% of the people have been exposed to the fungus. Most people don't develop any symptoms.

The following groups are more likely to develop symptoms of the infection:

• elderly individuals
• individuals with chronic lung disease, such as COPD
• infants
• people with immunodeficiency disorders, such as HIV infection
• young children

People with AIDS or cancer are more likely to develop disseminated histoplasmosis.

People at high risk for histoplasmosis should avoid contact with soil contaminated by bird or bat droppings. These areas include caves, poultry houses, barns, and other enclosed spaces.

Diagnosis of histoplasmosis begins with a medical history and physical exam.

The healthcare professional may order the following tests:

• an antibody titer test
• chest X-ray
• tests of urine, blood, and other tissues to look for the fungus

Many people with histoplasmosis have only mild symptoms that go away by themselves. Occasionally, the infection can cause severe respiratory insufficiency and even death.

Histoplasmosis is not contagious and cannot be passed from person to person.

Most people with histoplasmosis have mild cases that do not need to be treated. More serious cases can be treated with amphotericin B, ketoconazole (i.e., Nizoral), itraconazole (i.e., Sporanox), or fluconazole (i.e., Diflucan, although this is not FDA approved for histoplasmosis).

Amphotericin B can cause chills, fever, low blood pressure, and kidney damage. Fluconazole and itraconazole may cause liver disease. Any of the medicines can cause allergic reactions.

People with HIV infection may need to remain on lifelong therapy to prevent relapse of the histoplasmosis.

Any new or worsening symptoms should be reported to the healthcare professional. Special blood tests can be used to detect relapse.