Tuberculin skin test algorithm to determine the difference between boosted TST reactions and reactions due to recent infection with M. tuberculosis.

Two-Step Tuberculin Skin Testing (TST) (PDF)

Purpose: To determine the difference between boosted TST reactions and reactions due to recent infection with M. tuberculosis.

Use: Initial baseline skin testing of adults who will be retested periodically.

TST algorithm to determine the difference between boosted TST reactions and reactions due to recent infection with M. tuberculosis.

*using 5, 10, or 15 mm cutoffs, depending on person's risk factors for TB

Adapted from CDC