Histoplasmosis is also known as "Cave disease," "Darling's disease," "Ohio valley disease / fever," "Reticuloendotheliosis," and "Spelunker’s Lung”. This disease is caused by the fungus Histoplasma capsulatum. Symptoms of this infection vary greatly, but the disease primarily affects the lungs. Occasionally, other organs are affected; this is called disseminated histoplasmosis, and it can be fatal if left untreated. Histoplasmosis is common among AIDS patients, cancer patients, and other with autoimmune disease because of their suppressed immune systems.
It was once thought this disease was not common throughout the U.S. and more prevalent to the Midwest regions of the United States. However, that information has now been proved incorrect as many persons throughout the United States have tested positive for this disease. Many people who have contracted Histoplasmosis are “ A symptomatic” (showing no symptoms of the disease) however, they still test positive for the disease, which can manifest at a later time.
If symptoms of Histoplasmosis infection occur, they usually will start within 3 to 17 days after exposure; the average is 12–14 days. Most affected individuals have clinically silent manifestations and show no apparent ill effects. The acute phase of Histoplasmosis is characterized by non-specific respiratory symptoms, often cough or flu-like. Chest X-Ray findings appear to be normal in 40–70% of cases. Chronic Histoplasmosis cases can resemble tuberculosis. Disseminated Histoplasmosis affects multiple organ systems and is fatal unless treated.
While Histoplasmosis is the most common cause of mediastinitis (inflammation of the tissue in the mid-chest area), severe infections can cause hepatosplenomegaly (enlargement of the liver or spleen), lymphadenopathy (disease of the lymph nodes), and adrenal enlargement. Lesions have a tendency to calcify as they heal. Ocular Histoplasmosis damages the retina of the eyes. Scar tissue is left on the retina which can experience leakage, resulting in a loss of vision not unlike macular degeneration.