Hi, Thanks for writing in. It is important to know why you got Mantoux test done and any underlying clinical problems. Though very commonly used by physicians worldwide its interpretation always remains difficult and controversial. Various factors like age, immunological status coexisting illness etc influence its outcome, so also its interpretation. Utmost care is required while interpreting the result and giving an opinion. False-positive result may be caused by nontuberculous mycobacteria or previous administration of BCG vaccine. Prior vaccination with BCG may result in a false-positive result for many years later. Please discuss with a pulmonologist before starting medications for TB.