Patient: I had a TB test 12 days ago and they said the test was ok, for my job I needed another one ten days later. Friday the 3rd I got my second one it has been 2 days and it has started itching and burning and has a red center and is swelled around the center out a half inch all the way around. Is this ok, am I having an allergic reaction, do I need to have a dr. look at it. Thanks
Doctor: The test which you have undergone is called as mantoux screening test . It is a screening tool used for tuberculosis. Th e reaction is read by measuring the diameter of induration (palpable, raised hardened area) across the forearm. The test is positive in various other conditions apart from TB. It is a two step testing where in the first test is read 48-72 hrs after injection, If its negative a second test is done 1 to 3 weeks after the first injection. The second test is read 48-72 hrs after injection. if the second test is positive then you have to consider that you are previously infected. I would suggest you go see the doctor and he might ask you to go for further evaluation.