Is it okay to see the results of the PPD examination for tuberculosis for 75 hours?

Tuberculosis PPD is also known as PPD skin test, and the results of this test can be seen after 75 hours.

The PPD skin test is a test used to detect Mycobacterium tuberculosis infection. Tuberculin is usually injected intradermally into the flexor side of the forearm and the diagnosis of infection is based on the skin condition at the injection site. The results of this examination need to be observed after 48~72 hours, and if the results cannot be seen clearly within 48 hours, the results of 72 hours need to prevail.

Even after 72 hours, the results of the PPD skin test are still accurate in a short period of time, so the results can be seen after 75 hours.If there are no symptoms such as redness and induration at the injection site, it is a negative result, which can rule out the possibility of infection, but it also means that you have not been vaccinated with BCG. Conversely, if there is redness and induration at the injection site, it is a positive result and may be related to infection or BCG vaccination.

PPD skin test is not a standard for diagnosing Mycobacterium tuberculosis infection, and a positive result does not indicate a problem, and a comprehensive judgment based on physical signs and other examination reports is required. Once the diagnosis of infection and tuberculosis is confirmed, it is necessary to actively cooperate with the doctor for regular anti-tuberculosis treatment. During the treatment and recovery period, patients should pay attention to the combination of work and rest, strengthen indoor ventilation and disinfection, and reasonably mix three meals.