The tuberculin skin test, commonly referred to as TB, PPD mantoux skin test, is the method used to determine whether someone has exposure to tuberculosis. Tuberculosis is a bacterial infection that affects the lungs. It is a treatable condition, but in some countries it is still a common cause of death. The test will determine whether you are currently infected or have been previously exposed to the tuberculosis bacteria.
It is recommended to people who have symptoms of TB, exposure to the person who is known to have a TB and health care workers who will be potentially dealing with people with low immune system. Since disease can be contagious(via respiratory droplets), it has become a standard requirement for new school or job applicants.
The test is performed as follows: disinfection of the testing site (normally the forearm), our doctor will inject 0.1 ml of PPD (tuberculin purified protein derivative) into the top layer of your forearm skin, and when done correctly, it will form a small blister at the site of the injection.
If you have had an exposure to TB in the past you will develop a positive reaction to skin injection between 48 to 72 hours after administration. 2 to 3 days after the skin test you need to come back to see our doctor read the test results and document it. Only after it has been read is when you have completely fulfilled the tuberculosis skin test requirement, provided you have a negative result. If you miss the 48-72 hours window for the reading, unfortunately, you will have to redo the TB skin test.
Interpretation of the PPD skin test will be determined by measuring in millimeters the induration (the raised and palpable wheal formed after injection). The redness of the wheal plays no role in the reading of your test. The normal range for a negative tuberculosis skin test reaction in people with normal immune systems take place when an induration is less than 15 mm- anything that is greater or equal to 15mm is considered positive. Normal value ranges vary among people with underlying conditions (i.e. diabetes, AIDS, cancer, kidney disease), therefore notify our doctor if you have any health condition so you can be evaluated at the correct skin test range.
If you have a positive TB test result, do not alarm yourself. A positive PPD result does not necessarily mean that you have an active bacterial infection since people that have been in contact with someone with TB will produce a positive reading, and exposure does not translate into active infection. When you test positive, you will be asked to get a referal for chest x-ray in order to rule out active TB. If the chest x-ray comes back negative, then you will be given written clearance stating that there is no indication of presence of tuberculosis in your lungs- active disease
If you have a history of positive tuberculosis skin test, then there is no need to get another PPD test ever in your lifetime, as it will definitely yield a positive result. You can go ahead and get a chest x-ray to rule out presence of TB. Chest x-rays no older than 2 years and a medical note reporting no presence of TB symptoms is required to satisfy the tuberculosis screening requirement for schools or employers. Be aware that no patients can walk into a radiology center and get an x-ray, or any other health service, without a valid medical script (doctor referral ).
The tests are oftentimes covered by most major insurances. If for some reason your insurance does not cover the test, then our office can offer it to you for a simple fee of $60.*Chest x-rays are not covered under this fee and varies depending on the radiology center*
You will benefit from coming to the Walk-In Clinic NY to get your PPD skin test done because we understand that this requirement is time sensitive and relatively time consuming (you need at least 3 days:test day and 48-72 hours waiting period for the results) for acceptance of our patients into their new school or job. As a result, we offer you same-day/next-day appointments on most weekdays, extended evening hours, and Saturday appointments. Do not worry if you do not have a scheduled visit because we take walk-ins throughout our office operating hours. We understand that starting school or beginning a new job can be relatively expensive, the TB test is offered to you for a minimal fee of $60. Furthermore, our doctor can aid you in the complete process of obtaining medical clearance for your school or job, as we offer physical examinations. You can get everything done- physical, PPD test, MMR titers, etc.- all in one place at substantially low fees.