Disseminated histoplasmosis is a fungal infection that occurs after inhaling the spores of the fungus Histoplasma capsulatum.
Causes, incidence, and risk factors:
Histoplasmosis is caused by a fungus found in the central and eastern United States (Mississippi and Ohio River Valley), eastern Canada, Mexico, Central America, South America, Africa, and Southeast Asia.
Most cases are mild or without symptoms. Acute pulmonary histoplasmosis may occur in epidemics. Progressive or spreading (disseminated) and chronic disease can also occur. In disseminated disease, the infection has spread to other organs from the lungs through the bloodstream.
The liver and spleen are usually enlarged, and all body organs may be involved. Ulcerations of the mouth or gastrointestinal tract may occur. Risk factors are travel to or residence within the central or eastern United States, and exposure to the droppings of birds and bats.
- Joint pain
- Mental status changes
- Muscle aches and stiffness
- Nausea, vomiting
- Possible rash (erythema nodosum)
- Skin lesions
- Visual changes (chorioretinitis)
Signs and tests:
A physical examination may show abnormalities throughout the body.
Tests used to diagnose disseminated histoplasmosis may include:
Doctors prescribe antifungal medications to control the infection. Often patients need several months of treatment. Those who have suppressed immune systems (for example, from AIDS) might need lifelong treatment.
The disease may progress rapidly and death can occur.
Multiple organs are affected.
Calling your health care provider:
Call your health care provider if you develop symptoms of disseminated histoplasmosis, particularly if you have been recently treated for acute or chronic histoplasmosis.
Emergency symptoms include mental status changes and rapid worsening of the condition.
Avoiding travel to areas where this spore is found can prevent the disease, but this may not be practical. Avoid bird or bat droppings if you are in one of these areas, especially if you are immunosuppressed .
References: What LJ, Freifeld AG, Kleiman MB, Baddley JW, McKinsey DS, Loyd JE, Kauffman CA. Clinical practice guidelines for the management of patients with histoplasmosis: 2007 update by the Infectious Diseases Society of America. Clin Infect Dis, 2007;45:807-825.