In this test, the tuberculosis antigen is injected just under the skin with a multi-pronged instrument. The antigen is located on the tines (spikes) that penetrate the skin. The site, most often on the arm, is usually labeled with ink so that it may be monitored.
After 48 to 72 hours, if the result is positive, the skin will appear red and swollen like a mosquito bite where the antigen was injected. A negative test result may be a bit red but will not be swollen and firm like a mosquito bite.
Note: The tuberculin skin test is more accurate than the tine test and is the preferred method of determining exposure to tuberculosis.
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