ppd-tuberculin skin test
ImmunologySkin (intradermal) sampleResults 2-3 daysNo fasting
PPD-TUBERCULIN SKIN TEST
A skin test that checks for a tuberculosis-related immune reaction. A small amount of tuberculin is injected and the skin response is read after 2 to 3 days.
Sample
Skin (intradermal)
Results
2-3 days
Fasting
Not required
Follow-up
Optional add-on
What this test detects
Tuberculin skin reaction
Intradermal Mantoux
Induration in mm read at 48–72h
When to get this test
TB exposure screening
Used for people who may have been in contact with tuberculosis.
Latent TB assessment
Helps identify a past immune response to TB even without symptoms.
Pre-employment or school requirements
Often required for health clearance and institutional screening.
How to prepare
01
Return in 48–72 hours to have the skin reaction read.
Common questions
Why do I need to come back after a few days?
The skin reaction takes time to develop, so the raised area is measured 48 to 72 hours after the injection.
Does a positive reaction mean I have active TB?
Not necessarily. It shows your body has reacted to TB at some point, and further tests may be needed to check for active disease.