I had the Mantoux test 24 hours ago and am showing no reaction yet. I have never had a test before, am not on any immunosupressant drugs or suffering from any such diseases, but I have spent time in countries when TB is prevalent - if I am likely to react when will it begin to show? I realise that the test will not be read for another 24 hours, I am just wondering when a reaction will begin.
Hello dear, Thank you for your contact to Chat Doctor. I read and understand your concern. I am Chat Doctor answering your concern. Tuberculin test or manitou test is the test to know allergic reaction to protein part present in the body because of the infection. If you are infected with tuberculosis, you have infected protein in the body. And so you are allergic to the protein part. The reaction will start after the 48 hours. So you have to wait 24 hours more to start up reaction. If you have spent time in the tuberculosis prone country you will be exposed to the infection and so you are prone to the positive reaction. Positive reaction does not mean you are having a TB right now. Instead, it means you are exposed to the infection once. Induration in the reaction is counted while erythema and wheal is ignored. If the horizontal diameter of the reaction is more than 10 mm than it is positive reaction. I will be happy to answer your further concern on bit.ly/ Chat Doctor. Thank you, ChatDoctorInfectious diseases specialist, ChatDoctor.