The Mantoux Test or the Mendel-Mantoux test is a test that is used to diagnose tuberculosis or for the screening of tuberculosis. The test is known by several other names like the tuberculin sensitivity test, PPD test, the Mantoux screening test or the Piquet test. It is actually among the major tuberculin tests that are used around the world. It has largely replaced the multiple puncture tests like the tine test. The predecessor to the Mantoux test was a form of tine test, the Heaf test.
Tuberculosis is very contagious and is the result of an infection caused by the Mycobacterium tuberculosis bacteria. If a person is exposed to the bacteria, a latent TB infection or an active TB disease may result. The latent TB would mean that the person is infected but there are no symptoms or signs of the disease. This latent TB could also become an active TB disease. There is a combination of medications available which has to be administered for 6 to 9 months to treat the active TB disease. The latent TB is also treated in a similar way to prevent further development into an active disease in the future. Two types of tests are available to diagnose TB – a skin test and a blood test, neither of whose results would reveal if you have an active or latent form of tuberculosis. They help to determine if there should be any treatment and the type of medication that is to be used. The liver blood test does a similar function where it measures the level of SGPT and determines if you need to be treated for liver damage.
What would happen during the Mantoux test?
The TB skin test is just another name for the Mantoux tuberculin skin test. Tolerance to the test is very good and people generally do not have any negative reaction to it. The TB skin test is mostly performed in two parts:
- During the first part of the test, the patient visits the office or clinic of the doctor where a tiny amount of tuberculin would be injected under the skin. The forearm is generally preferred for the process. Produced from the bacteria that causes TB, tuberculin is a sterile extract – a purified protein derivative (or PPD). A small, pale bump is formed at6 the site after the injection is received.
- After about 48 to 72 hours later, the second phase of the mantoux test takes place. The doctor looks at the skin to check how it has reacted to the tuberculin. The skin reaction would help the doctor determine if there has been any TB infection. You would need to start over with a new test and a new injection would need to be administered if you wait longer than 72 hours. If this is the first TB skin test and the result is negative, the doctor might ask you to return in about three weeks’ time for the test process to be repeated. This is to ensure that the test results are the same.
What would follow if the test results are positive?
If the test result is positive, a chest X-ray would follow. This would help to determine if there is an active TB disease or the infection is latent. The doctor checks for white spots which are the areas where the immune system is responding to the presence of the bacteria. The doctor might use a CT scan to see if there is any other change caused by the disease. The CT scan provides greatly detailed images. An ESR test might reveal if there is any inflammation. The doctor might even order tests on the sputum, which is the mucus produced during a cough. The laboratory test would help to identify the type of tuberculosis bacteria and the doctor can then take necessary actions.