<prompt> Tuberculin test is said to be positive when there is.IndurationErythemaErythema, indurationInduration with blistering  <response>: - A positive tuberculin test is when an induration of diameter 10 mm more is present. - erythema is not taken into account. - It indicates hypersensitivity to tuberculoprotein, denoting infection with tubercle bacilli or BCG immunisation , recent or past with or without clinical disease. Reference : Anathanarayan paniker;s 9th edition, pg no: 354,355 