What is histoplasmosis?
Histoplasmosis is an infection caused by the fungus, Histoplasma capsulatum, that primarily affects the lungs but may spread to other parts of the body.
What causes histoplasmosis?
Histoplasmosis is caused by Histoplasma capsulatum a type of fungus. The spores of H. capsulatum are s distributed worldwide, but common in the central and southeastern states of the U.S.; Central and South America, and other areas with big river valleys. It is found in soil and in the droppings of bats and birds, especially their roosting areas, such as in caves, chicken coops, and older barns.
These spores can be released into the air and breathed in when contaminated soil or droppings are disturbed. People cannot spread the infection to each other.
People at higher risk of developing histoplasmosis include farmers, construction or demolition workers, landscapers, and those with a weakened immune system such as people with AIDS, undergoing chemotherapy for cancer, or taking corticosteroids or TNF inhibitors for rheumatoid arthritis.
What are the symptoms of histoplasmosis?
Most people who are infected with histoplasmosis have no symptoms. However, the likelihood of symptoms increases the more spores that are breathed in and may include:
- Chest pain
- Dry cough
- Joint pain
- Red bumps on the skin of the lower legs.
More severe symptoms, such as excessive sweating, shortness of breath, or coughing up blood are more likely with significant infection. Symptoms of histoplasmosis are generally more severe with the first infection compared to subsequent infections.
It may take up to ten days after exposure for symptoms to show.
How is histoplasmosis diagnosed?
Because most cases of histoplasmosis are symptomless, most people never know they are infected. However, testing for histoplasmosis may be considered in people with severe infections or who live or work in high-risk areas.
Your doctor will ask you about where you live and work, and any symptoms you may have. They may conduct blood, sputum, or urine testing to check for antibodies or proteins that indicate you have been exposed to histoplasmosis. These can take up to six weeks to get results.
Other tests such as biopsies or imaging tests may also be needed.
How is histoplasmosis treated?
Most cases of histoplasmosis don’t require treatment. However, treatment may be necessary for people with weakened immune systems (such as those with HIV) or when the infection has spread throughout the body. These people are at higher risk of complications which may be life-threatening.
Treatments may include antifungals, such as ketoconazole, itraconazole or amphotericin B.