Are there any dangers from repeating a PPD test for tb?

Only if positive. Patients who have had a positive PPD should not ever have it repeated because there is the potential for a very severe reaction at the injection site, occasionally leading to loss of tissue and even the need for surgery and skin grafting. Actually, people who are negative may have the test done again shortly afterwards for the so-called booster effect.
Only if positive. Patients who have had a positive PPD should not ever have it repeated because there is the potential for a very severe reaction at the injection site, occasionally leading to loss of tissue and even the need for surgery and skin grafting. Actually, people who are negative may have the test done again shortly afterwards for the so-called booster effect.