TUBERCULIN TEST ( TT ) (MONTOUX TEST)

The Mantoux test, also known as the tuberculin skin test (TST), uses a solution called tuberculin, or purified protein derivative (PPD), that's injected into the skin with a syringe and needle: InjectionA healthcare provider injects 0.1 mL of tuberculin into the forearm using a small needle. The injection should create a firm, pale wheal that's 6–10 mm in diameter. ReadingAfter 48–72 hours, the healthcare provider measures the diameter of any palpable induration (raised, hardened area) across the forearm. Follow-upThe healthcare provider must check the arm again 2–3 days after the test, even if the arm looks okay. If the injection is unsuccessful, the provider can repeat it on the other arm or at least 5–10 cm from the first site.