that tb test (probably a ppd) does not determine if a person has tb but just that the person may have been exposed to tb. other tests like a chest x-ray are usually required to make a definitive diagnosis. a positive tb test does not typically act like this but rather develops an induration (a depression) not a red bump and rash so there may be an allergic reaction of some sort. this tb test should have been read at 48 hours. not waiting this long so he may need to have it repeated and properly red.
what if tb shot is given and it turns into red bump. my son received a tb shot on a wednesday. doctor said i didn't have to come back till monday because that was an appointment for me. so by thurs and fri my son had a huge red bump where shot was given and a rash up his arm. does he have tb? .