Hi doctor, I had a TB test done at 9:30 AM yesterday and it is now 7:30 PM. The area is itchy, swollen with a red ring around it. Should I be worried?
Hi.  I believe that you have undertaken the Mantoux skin test. There is likely to be an initial inflammatory reaction to the tuberculous killed bacillus which can form the ring and itch slightly. You may apply an emollient over it. This test is to be studied after 48 hours for results where if the induration is more than 10 mm in diameter then the test is positive and the patient is said to be susceptible to tuberculosis. Then is followed by ADA (Adenosine deaminase) and/or MTB-PCR (Mycobacterium tuberculosis-polymerase chain reaction) test to confirm the diagnosis further.