PPD: The hardness (induration) of the reaction to the test is the basis for determining a positive test. Any erythema visible really has no significance.
Answered 9/23/2018
5.7k views
2 doctors weighed in across 2 answers
A doctor has provided 1 answer
A doctor has provided 1 answer
A doctor has provided 1 answer
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more.
Ask your question