12-06-2011, 04:08 PM
(A) Do nothing
Explanation:
If the patient had not developed tuberculosis because of the previous exposure, she is not going to now. A positive skin test confers a 10% lifetime risk of developing tuberculosis. Almost all of this is within the first two years of developing a positive reaction. There is no point in giving a patient isoniazid now to prevent tuberculosis that would have happened years ago after the initial exposure. Once a tuberculosis skin test is positive, there is no point in ever repeating the test. It will always be positive. There is no benefit to yearly chest x-rays in anyone. Two-stage PPD testing is performed in those who have either never been tested before or who had negative skin tests in the past and it has been longer than a year since the last positive test. The two-stage test is to confirm that the first test is truly negative.
Explanation:
If the patient had not developed tuberculosis because of the previous exposure, she is not going to now. A positive skin test confers a 10% lifetime risk of developing tuberculosis. Almost all of this is within the first two years of developing a positive reaction. There is no point in giving a patient isoniazid now to prevent tuberculosis that would have happened years ago after the initial exposure. Once a tuberculosis skin test is positive, there is no point in ever repeating the test. It will always be positive. There is no benefit to yearly chest x-rays in anyone. Two-stage PPD testing is performed in those who have either never been tested before or who had negative skin tests in the past and it has been longer than a year since the last positive test. The two-stage test is to confirm that the first test is truly negative.