The PPD skin test is a test done which can tell whether someone has at one time been exposed to tuberculosis. The test can not tell whether someone actually has active tuberculosis, and can't tell if they ever did. It only tells us whether the tuberculosis bacteria ever made it into the person in question. PPD tests are not done on everyone. This is because tuberculosis is not that common in the United States and testing everyone every year would be a waste of time and money.
People that should be tested every year are people that work in the health care field directly with patients (doctors
, nurses, etc.), and people that travel abroad (such as members of the armed services). In addition, anyone else that is known to have come into contact with someone with tuberculosis should have a PPD test. Unless your son fits into one of these categories, he probably doesn't need to have it done.
I suggest that you schedule an appointment for your son with his pediatrician
. The two of you can discuss all the annual testing that is routine for boys his age (there isn't much) and make sure that your son is up to date with his health care.