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Histoplasmosis is a lung disease caused by breathing in airborne spores. These spores rise from soil that contains a fungus called Histoplasma casulatum. It is possible to have histoplasmosis and be unaware of it, because many people never develop any signs or symptoms of the infection. However, histoplasmosis can be life-threatening. It occurs most often in temperate regions of the world, and in the United States is common to the areas around the Ohio, Missouri, and Mississippi Rivers.

There are several different kinds of histoplasmosis, with various symptoms and varying degrees of severity.
 Asymptomatic primary histoplasmosis is the most common type of this illness. It usually causes no symptoms if the person who is infected is otherwise healthy. In some cases, there may be small scars in the lungs.


Acute symptomatic pulmonary histoplasmosis is more serious. It occurs in otherwise healthy people who have had prolonged exposure to the fungus. The symptoms of this stage of the illness depend on the severity of the infection and the number of spores inhaled. You might feel a bit under the weather, or you might become seriously ill. Symptoms can include fever, headache, dry cough, chills, chest pain, weight loss or sweating. In some severe cases, arthritis or pericarditis may develop weeks or even months after the initial infection. In some cases, you may develop severe acute pulmonary syndrome, a serious condition in which breathing becomes difficult.
 Chronic pulmonary histoplasmosis affects people who already have lung problems. It is most common in white, middle aged men, and is dangerous if left untreated. Its symptoms include fatigue, fever, night sweats and a cough that brings up blood.
 Disseminated histoplasmosis occurs most often in young children and other people with compromised immune systems. This form of histoplasmosis can affect any part of the body, including eyes, liver, bone marrow, skin, adrenal glands and intestinal tract. If this form of the illness is left untreated, it is fatal. Symptoms may depend upon which organs or systems are affected, but they can include anemia, pneumonia, inflammation of the lining around the heart, meningitis, or ulcers of the mouth, tongue or intestinal tract.


Anyone who is exposed to the fungus is likely to become infected. The fungus lives in damp soil, often in river valleys, and it is found in the droppings of birds and bats. In addition to being found in rich soil, the fungus can be found in chicken and pigeon coops, old barns, caves, and parks. You can catch it from the droppings of bats, such as can be found in caves. You develop histoplasmosis when you inhale the spores of the fungus. They easily enter your lungs and settle into the small air sacs, then are carried by the immune system into the lymph nodes as well. In some cases, the fungus will be carried to other parts of your body will it will reproduce unless your immune system can expel it efficiently.

Because exposure almost guarantees infection, some people are very likely to develop histoplasmosis. These can include
 Those who work with soil
 Those who work with bats
 Those who work in caves
 Poultry keepers
 Pigeon keepers or trainers
 Construction workers
 Landscapers or gardeners
 Grave diggers/robbers
 Treasure hunters
 Road crews
Image: Histoplasmosis


Histoplasmosis can sometimes be difficult to diagnose, because its symptoms are common to other illnesses as well. Some tests that your doctor might wish to conduct include
 A fungal culture. This test is one of the most effective in detecting the presence of histoplasmosis. In this test a small amount of material—such as blood, sputum or tissue—from your lymph nodes, lungs, or bone marrow is put into a culture and grown, then tested for the presence of the fungus. This is a very accurate test, but the drawback is that it takes anywhere from two to four weeks, and sometimes up to twelve weeks, for the culture to grow. Because of this delay, the fungal culture is not a good test for those whose histoplasmosis may be so advanced that delay might prove fatal.

 Fungal stain. In a fungal stain, a tissue sample is stained with dye and examined under a microscope. The reliability of this test depends on the quality of the sample and the skill of the examiner, because other fungi can resemble Histoplasma casulatum. This test usually requires a second test to make sure the first results were accurate.
 Serology. This is a blood test that examines blood for antigens and antibodies. However, false negatives can be a problem, so this test must be conducted multiple times to ensure that the results are accurate.
 Chest x-ray. This can show damage and inflammation in your lungs.
 CT scan. This can show more details of damage or inflammation, and determine whether there have been complications.
 Bronchoscopy. In this test the doctor inserts a tube with a light on the end into your trachea, and can take a small sample of tissue if desired.


If histoplasmosis reaches a level where it produces symptoms or is disseminated throughout the body, it can lead to severe complications.
 Enlarged lymph nodes—if these are very swollen it can block passages used for breathing or swallowing.
 Fibrosing mediastintis—this occurs when scar tissue from lymph nodes blocks the esophagus and large blood vessels.
 Pericarditis—this happens when the sac that surrounds the heart becomes inflamed.
 Arthritis—this occurs as a complication of acute pulmonary histoplasmosis.
 Adrenal insufficiency—when the adrenal glands function inefficiently, life-threatening complications can ensue.
 Meningitis—this is an infection of the lining of the brain and spinal cord, and can be life threatening.


Treatment is not always necessary, but in more serious cases, you may need treatment with a strong anti-fungal medication, such as amphotericin B or itraconazole. The first of those must be administered intravenously, so doctors usually begin with it, then switch to itraconazole.
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Medication commonly used for these disease:

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