What does a positive Mantoux test indicate?

Q: My 49 years old mother has been tested for Mantoux test and the report stated 24 mm positive (more than 10 mm with erythema and induration is taken as positive). Please suggest medication for this and also necessary steps to be taken for immediate and permanent cure?

A:In your mother's case, a strongly reactive Mantoux means that she has been exposed to tuberculosis bacilli and she has developed hypersensitivity to tubercular protein, which is measured by the diameter of induration (red swelling) after 48-72 hours that develops at the site of tuberculin injection given intradermally (in the skin of the forearm). A positive Mantoux test doesn't always mean someone has TB disease; it just means that the bacteria have been in the body at some time. Also, a diagnosis of tuberculosis is never based solely on a Mantoux/PPD tuberculosis test. False-positive reactions to the tuberculosis skin test can occur because of:

• Infection with non-tuberculous or atypical mycobacteria
• BCG vaccine
• Booster phenomenon

Your mother's doctor should check her carefully, looking for any symptoms and signs of tuberculosis. The next step is to get an X-ray of the chest to check for tuberculosis infection in the lungs along with a sputum test for AFB - smear and culture. If TB is diagnosed, the treatment lasts six to nine months, depending on the clinical condition. A combination of isoniazid, rifampicin, and ethambutol (along with one more drug in some cases) is usually prescribed daily. Your mother's doctor will do some blood tests and want to see her regularly to monitor any side effects of drugs. Its very important that she take all the medication as directed; otherwise, it may not work, and the TB bacteria could continue to grow or become resistant. Once the Mantoux is positive it stays positive, even after treatment.