Histoplasma Skin Test

Histoplasmosis is an air borne infection caused by the Histoplasma capsulatum fungus that generally affects the lungs and has a tendency to spread to organs and tissues outside the lungs. People who are prone to this infection are farmers, landscapers, construction workers and people who come in contact with bird or bat droppings. Affected people usually never develop symptoms or are aware of the infection. The problem can get serious for infants and those with lower immunity.

This infection can lead to a number of serious complications, even in otherwise normal healthy people and can be life-threatening for infants and people with lower immunity. Problems can range from enlarged lymph nodes, severe scarring, heart problems, arthritis, and adrenal insufficiency. The many signs and symptoms of this infection resemble those of other illnesses. It becomes difficult to diagnose in such a complicated state.

To detect the infection and the presence of the fungus, there are a large number of tests which have their own limitations like fungal culture (takes approximately 4 weeks), urine and blood tests, and fungal stain. Tests like chest X-ray, computerized tomography (CT) and Bronchoscopy are conducted depending on  the severity of the signs and symptoms of the infection.

Doctors use a method known as histoplasma skin test on patients to known if they have been exposed to this infection. A well known method that is used to check if a  After a routine visit to the doctor and a battery of queries on the usual symptoms and the like, the test will be conducted. No elaborate preparation or arrangement is required for such a test. During the test, only a small sting will be felt at the time the needle is inserted. Generally, an area with hair, usually the forearm is selected for the skin test. After that patch is cleaned, an allergen will be injected just below the skin surface. The injected site is under constant monitor every 24 and 48 hours for signs of any reaction. It may so happen, the reaction won’t take place or appear until the fourth day. If there is no inflammation of the site of the test, then it is normal. Sometimes, the skin test can turn the antibody tests positive. People undergoing such a test could run the risk of a slight anaphylactic shock ( a severe reaction). This test is rarely used these days, there are a variety of other blood tests.