Mantoux test and its procedure

The Mantoux test or Mendel-Mantoux test (also known as the Mantoux screening test, tuberculin susceptibility test, Pirquet test, or PPD test of purified protein derivatives) is a screening tool for tuberculosis (TB) and diagnosis of tuberculosis.It is one of the main tuberculin skin tests used in the world and largely replaces multiple prick tests such as the tine test.The Heaf test, a form of the tine test, was not used in the UK until 2005, when it was replaced by the Mantoux test.The Mantoux test is endorsed by the American Thoracic Society and the Centers for Disease Control and Prevention.It was also used in the Soviet Union and is now popular in most post-Soviet countries, although Soviet mantoux has produced many false positives due to allergic reactions in children. 

Procedure

In the Mantoux test, the standard dose is 5 tuberculin units (TU - 0.1 ml) according to the CDC, or 2 TU Statens Serum Institute (SSI) tuberculin RT23 in 0.1 ml solution according to the National Health Service Intradermal injection (between the layers of the dermis) on the flexor surface of the left forearm, midway between the elbow and wrist.Injections should be given with a tuberculin syringe with the bevel of the needle pointing up. If placed correctly, the injection should produce a pale wheal on the skin that is 6 to 10 mm in diameter.Test results are read after 48-96 hours, but 72 hours (Day 3) is ideal.This intradermal injection is called the Mantoux technique.People who have been exposed to the bacteria are expected to develop an immune response in the skin containing bacterial proteins.This reaction is a classic example of delayed-type hypersensitivity (DTH), a type IV hypersensitivity reaction.T cells and myeloid cells are attracted to the site of reaction within 1-3 days and produce local inflammation.Responses were read by measuring the diameter in millimeters of indurations (palpable raised, hardened areas) across the forearm (perpendicular to the long axis).If there is no induration, the result shall be recorded as "0 mm".Erythema (redness) should not be measured.In the Pirquet version of the test, tuberculin is applied to the skin by scratching.