Bathing after a TB skin test may cause infection at the skin test site, which in turn may affect the determination of the TB skin test result.
The TB skin test, also known as the tuberculin test, is a method used to screen the population for Mycobacterium tuberculosis infection. After the tuberculin test, the diameter and color of the nodules at the skin test site, and the presence or absence of ulceration are used to determine whether or not the body is currently infected.
Bathing after the tuberculin test, the skin test site may be stained with water, which may lead to the occurrence of pain, itching or even bacterial infection at the skin test site, and the size and color of the stress may also be affected, thus affecting the determination of the tuberculin test results and leading to the appearance of false positives.
To summarize, try to avoid bathing after the tuberculin test.