Tomorrow we are scheduled to get the result of our little guy's lab exam called the PPD skin test. When I looked it up and to know what it means, here's what I have learned from MedlinePlus:

"The purified protein derivative is an antigen (a substance that stimulates the immune system to eliminate or fight foreign substances in the body), which is injected under the skin in the forearem. After 48 to 72 hours the injection site is evaluated by a physician. This skin test helps determine if a person has ever been infected by the microorganism that causes tuberculosis."

Our little guy's x-ray result came back that he has Primary Complex, from how I understand it, this PPD skin test will tell us the extent of it. I am not really sure. Can anyone tell me?