Mantoux Test (Tuberculin Skin Test)
A skin test that shows whether you've been infected with TB bacteria.
Quick Summary
To check for TB infection, especially in children and contacts.
Size of the raised area where tuberculin was injected.
No preparation.
Overview
A small amount of tuberculin is injected under the skin of the forearm.
BCG vaccine can cause a positive result, so it's interpreted carefully.
What It Measures
Induration
Size of the hard, raised area.
How It's Performed
- 01
Injection
A tiny injection under the skin.
- 02
Wait
Don't scratch or cover the area.
- 03
Reading
Return after 48–72 hours to have it measured.
Interpreting Results & Next Steps
Discuss with Doctor
Your doctor will explain what your result means and what happens next.
If values are High:
A larger reaction suggests TB infection; it doesn't show whether TB is active.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Tuberculosis Screening(opens in a new tab) · MedlinePlus, US National Library of Medicine