Identification

The skin test for tuberculosis, called the Mantoux test, uses a small amount of the purified protein derivative tuberculin (derived from tuberculosis bacteria). Tuberculin is injected into the skin to test for tuberculosis.

Effects

If a person has tuberculosis, the test will cause a hard red bump to appear where the injection was given, according to the Mayo Clinic.

Features

A tuberculosis skin test is used mostly as a screening tool to find tuberculosis in specific groups of people, such as those with weakened immune systems, people in prisons, nursing homes and schools, people in the health professions, individuals who have been exposed to someone with active TB or who have lived somewhere where TB is common, pregnant women and possibly before starting a new job or enrolling in a new school, according to Lab Tests Online.

Warning

There is some risk of false-positive and false-negative results in a tuberculosis skin test, according to the Mayo Clinic.

Considerations

Further tests, such as chest x-ray and bacterial cultures are necessary to see if a person has active TB, meaning that they could infect others, according to Lab Tests Online.

Source:

Mayo Clinic: Tuberculosis Tests and Diagnosis

Lab Tests Online: TB Skin Test