A student health nurse is conducting tuberculosis (TB) testing. Students who had the purified protein derivative (PPD) test 48 hours ago have returned to have the results read and documented. The nurse determines that the test is positive if which of the following is present?
1) The client complains of itching at the site
2) There is a large area of erythema
3) There is an induration of 10 mm or greater
4) A bruise is present at the site of injection