Explanation of the 2-Step PPD TB Test Process:

A 2-step TB test consists of two separate TB skin tests and detects latent TB, exposures from the distant past that do not elicit a response to a single skin test.

The second test must be planted no earlier than one week after the first test was planted and no later than three (3) weeks after the first test was planted.

It is possible to complete the 2-step in only three (3) office visits. This takes the shortest amount of time.

• Day 0: plant the first test
• Day 7: plant the second test if there is still no evidence of a reaction from the first test.
• Day 9 or 10 (48-72 hours after the second test was planted): read the second test.

** This requires you to have had the second test planted on Day 7. Otherwise, you should have had the first skin test read 48-72 hours after it was planted.

If you cannot get the second test on Day 7, you will need to follow this schedule:

• Day 0: plant the first test
• 48 - 72 hours after the first test: read the first test
• Day 8 - 21: plant the second test
• 48 - 72 hours after the second test: read the second test

Alternatives to 2-step TB skin tests are (1) a Quantiferon Gold test or (2) a chest x-ray within the past 2 years and a Review of Symptoms form.

Once latent TB has been ruled out, only a 1-step skin test is required annually.

• For those with a Quantiferon Gold test, the Q Gold or skin test is required annually.
• For those with a chest x-ray, only the Review of Symptoms form is required annually.