A TB skin test is a simple way to find out if you have latent/inactive TB. A small needle will be used to inject a small amount of liquid called tuberculin just under the skin on your arm.
You must return to the health unit 2 days after the test is given to have your arm checked, even if your arm looks okay to you.
As of June 5, 2017, TB skin testing at Elgin St. Thomas Public Health will be by appointment only for Elgin County residents. Please call 519-631-9900 ext. 1200 to book an appointment. Online booking is not available for TB Skin Testing.
Elgin St. Thomas Public Health
1230 Talbot St. St. Thomas, ON
Mondays from 9:30 am - 12:30 pm
Wednesdays from 1:30 pm - 4:00 pm
For more information on TB skin tests or alternative testing locations, call the health unit at 519-631-9900
TB skin tests are $40 per step ($80 for a two-step). Cash or debit only.
TB skin tests are free for people who are:
- contacts of an active case of TB;
- undergoing treatment or have a medical condition that makes them more likely to develop active TB;
- new to Canada and need the test for immigration medical surveillance;
- required to have a TB skin test by an educational institution for admission or continuation in a day care or pre-school program, or a program of study in a school, community college, university or other educational institution.
A two-step skin test means that you need two TB skin tests. The second test should be given 1 - 4 weeks after the first. The 2-step skin test needs to be done ONCE only and never needs to be repeated.
A two-step test is recommended for people who will need repeat TB skin tests in the future (e.g. health care providers).
A TB skin test is “positive” if there is a certain size bump where the fluid was injected. This means you might have TB germs in your body. Most people with a positive TB skin test have latent/inactive TB infection. Your health care provider will examine you and send you for a chest x-ray after a positive TB skin test. You may need other tests to see if you have active TB disease
- There may be slight swelling, redness, bruising or itching at the site, this is normal.
- Do not cover the test site with a bandage.
- Be careful not to rub or scratch the test site. If the area itches put a cold cloth on it.
- You can wash your arm and dry it gently.
- Anyone with a history of a positive TB skin test in the past;
- Anyone who has been diagnosed or treated for active or latent TB in the past;
- Anyone who has had a live vaccine must wait 4 weeks before having the TB skin test;
- Anyone who has had a recent major viral illness in the past month;
- Anyone who has had an allergic reaction to the TB skin test in the past.
The following are NOT contraindications for TB skin testing: pregnancy, breastfeeding, past history of BCG vaccination, vaccination with a non-live vaccine in the past 4 weeks or treatment with low-dose steroids.