Tuberculosis Skin Testing

Tuberculosis (TB) is a serious, potentially life threatening, bacterial infection of the lungs.This infection may be spread through droplets of bacteria that are released when an infected person talks, coughs, spits or sneezes. Unlike most other infections, the majority of people infected with tuberculosis do not suffer from any symptoms of the disease as the infected cells can remain dormant for many years. Only a small percentage of those infected with TB have cells that multiply and cause sickness. Although TB infections are rare in the United States, people with weakened immune systems, people who travel to countries that have high rates of TB, or people who work in the healthcare industry, are at a greater risk for developing a TB infection.

A primary method of testing for the presence of a tuberculosis infection, is a simple skin test called a PPD (purified protein derivative) test. This test is used to assess whether the body produces a reaction that indicates the existence of tuberculosis bacteria. During the PPD test, a small amount of purified protein derivative is injected just below the surface of the skin. Two or three days after the initial test, the individual returns to the doctor for an examination of the injection site. If the area is considerably swollen, and has a hard raised bump, it is considered a positive result for a tuberculosis infection. Because PPD tests are not always completely accurate, a positive TB result is often followed by blood tests, mucus or sputum testing, and a chest X-ray to confirm a positive diagnosis.

Tuberculosis is usually treated with medication that may be needed long-term. Antibiotics may be prescribed for as long as 6 to 9 months. Treatment may vary for people with drug-resistant infections or those who have HIV or AIDS. It is important for individuals diagnosed with TB to complete the long treatment in order to successfully treat the disease. Stopping treatment earlier than prescribed may lead to a TB infection that is much more serious and difficult to treat.

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