Tuberculosis (TB) is one of the most potentially infectious diseases that usually occurs in the lungs. Mycobacterium Tuberculosis, the bacteria that causes TB, spread through the air from common actions such as sneezing and coughing. Unfortunately, it means you are more susceptible to get infected with it during the Winter season, especially if you have a weak immune system.
There are tests that can help determine whether or not you’ve contracted tuberculosis: a TB blood test and a skin test. Although the Centers for Disease Control and Prevention (CDC) has provided guidelines on how to administer an Interferon Gamma Release Assay or IGRA blood test, a skin test is still the standard testing method in most health care facilities. Read more to learn about the PPD test and if it is crucial that you get one.
What Is TB Testing?
The fastest way to get this testing done is in 48 hours. Then, doctors check your response to the test at 72 hours, after which you need to wait before the test can be re-done on a different part of the skin.
Important Things To Know About TB Skin Tests
- Make sure that your doctors’ office will be open between 48 to 72 hours after the test. If you miss that second visit between 48-72 hours, the result becomes invalid.
- If you miss the second doctor visit, you’ll have to wait at least 7-10 days for another skin test.
- The doctor who administered the test should be the one to read the TB test results.
- Traditionally, the results are read as positive or negative. Nowadays, the doctor needs to know the size of the reaction in millimeters. If the reaction size is missing, it can become an issue with Federal and State requirements such as for purposes of Immigration.
- All subsequent medical decisions for PPD will be based on the size of the reaction, and your medical and demographic history.
What Happens When You Get a PPD Test?
A doctor injects a small amount (0.1 ml) of a PPD protein (called Tuberculin) into your skin. After 2-3 days, if your body identifies and reacts to the PPD shot, it means you must have been exposed to tuberculosis bacteria. The test cannot be read earlier than 2 days from the time of injection.
Allergy to band-aid glue is common and you want to be sure that nothing interferes with your test. After that, you go home and wait for 48-72 hours.
When to Read PPD Results and What Does a Positive TB Test Look Like?
When you arrive for the second part of your Tuberculin test, your doctor will look at the skin around the injection. The standard guidelines are to measure the area that looks reddish or pinkish (called Erythema) and record its size in millimeters.
Then, the area has to be felt by the examiner’s fingers to detect any raised, thickened, and firm skin inside the red or pink area. This hardened skin is called induration and its size also needs to be recorded in millimeters across the forearm, perpendicular to the long axis.
It takes a skilled, trained doctor to provide an accurate reading of negative and positive reactions, as well as to determine false-negative reactions, to determine if you have a latent TB infection or an active TB infection. Always choose a medical provider that does this test routinely.
Although retail pharmacies might offer a PPD test, pharmacists aren’t trained to read PPD results. TB is too serious of infection not to choose the most highly skilled medical professional to help you with testing and to determine if you need to get a chest x-ray and TB treatment.
So, Should You Get Tested?
If you live in NYC, where risk factors are high, the answer is simple: Yes, you need to search for “TB test near me” immediately. Exposure to Tuberculosis is common in NYC. Even if you got the BCG vaccine when you were younger, the protection fades away as you get older. It is important to not confuse BCG as a PPD vaccine.
If you think you may have been infected, been around someone who has TB or recently traveled to high-risk areas like hospitals and nursing homes, definitely ask for a TB PPD test near me as soon as possible. Come to Statcare for a 2 step PPD as well as all the answers and treatment options you need. We are here to help.