What is Mantoux Test?
Mantoux test is also known as Tuberculosis skin test and PPD test. It is used to diagnose the latent/ asymptomatic Tuberculosis (TB) infection. Tuberculin a purified protein derivative (PPD) made from TB causing bacteria is injected into the forearm of the patient and skin reaction after 48-72 hrs forms the basis of diagnosis of TB infection. In case of a positive mantoux test, a chest X-ray is also recommended.
Mostly a latent TB infection can result into active infection hence a prompt diagnosis and treatment is mandatory. It is preferred over other TB blood tests in case of children below 5 years. It is also advised to people came in direct contact with TB infected patients and immunocompromised people.
Why is Mantoux Test done?
- If you have signs or symptoms suggestive of tubercolosis like persistent cough, fever, night sweats, weight loss, fatigue
Interpreting Mantoux Test results
- The result of this test is interpreted in terms of induration (palpable, raised, hardened area) across the forearm in millimeters. If there is no induration, the result should be recorded as "0 mm" and it means that you have not been exposed to TB bacilli.
- Induration of 5 mm, 10 mm, and 15 mm is considered positive depending on the individual's risk factors. A positive test result indicates TB exposure.