do i need medication if my tb skin test is positive
1 People who have a positive TB skin test with a normal chest X-ray are NOT contagious, but may need medicine to prevent them from ever getting active TB. 2  Children under the age of 12 with active TB are rarely contagious, and do not need to be kept out of school.ow often does a TB test have to be repeated? If you have a negative skin test, you need a repeat test at least every four years. If you have a documented positive skin test, you must have an initial chest X-ray. After that, you still need to be screened every four years.