I had a TB test this morning

tokidoki7, ASN, RN · Aug 3, 2009

It should take 48 hours. When I got mine I had to return in two days to get it read.

nursej22, MSN, RN · Aug 3, 2009

Please note that the appearance of redness is not an indication of a positive test. After 48-72 hours a test is measured for the amount of induration at the injection site.

Bortaz, MSN, RN · Aug 3, 2009

Was it a multiple choice test? How many questions on the test? Was it difficult? Do you think you passed?

Yes, I'm delirious from end of semester testing.

lerabelle · Aug 4, 2009

The time in which you react actually depends on if you have been exposed to TB or have TB or not. If you have, it usually reads positive sooner rather than later. If you have not been exposed, you will not have any response.

waggykeeper · Aug 4, 2009

From what I have seen in those that test positive after 48-72hrs... sometimes the area doesn't start getting larger induration till the next day. If you you had it today its definitely too early to draw conclusions. Hopefully it stays the way it is now:)

SunnyAndrsn · Aug 4, 2009

the red area is not what is being measured.

here's a little information for you from http://www.medicinenet.com/tuberculosis_skin_test_ppd_skin_test/page1.htm

"the tuberculin skin test is based on the fact that infection with m. tuberculosis produces a delayed-type hypersensitivity skin reaction to certain components of the bacterium. the components of the organism are contained in extracts of culture filtrates and are the core elements of the classic tuberculin ppd (also known as purified protein derivative). this ppd material is used for skin testing for tuberculosis. reaction in the skin to tuberculin ppd begins when specialized immune cells, called t cells, which have been sensitized by prior infection, are recruited by the immune system to the skin site where they release chemical messengers called lymphokines. these lymphokines induce induration (a hard, raised area with clearly defined margins at and around the injection site) through local vasodilation (expansion of the diameter of blood vessels) leading to fluid deposition known as edema, fibrin deposition, and recruitment of other types of inflammatory cells to the area.

"reading" the skin test means detecting a raised, thickened local area of skin reaction, referred to as induration. induration is the key item to detect, not redness or bruising. skin tests should be read between 48 and 72 hours after the injection when the size of the induration is maximal. tests read after 72 hours tend to underestimate the size of the induration.

the area of induration (palpable, raised, hardened area) around the site of injection is the reaction to tuberculin. again, redness is not measured"

springsheen · Aug 4, 2009

I had a TB test last Tuesday, and a nurse told me I was negative for it on Thursday. However, it's been about a week and the redness is still there, and the area of injection is still slightly raised (very slight). Is this normal, and if so, how long does it take to go away? :confused:

adruiz01 · Aug 4, 2009

Thanks everyone for you input. . . .it has been almost 24 hours and I have no reaction to it besides the little tiny red spot where she poked me. So far so good :wink2: YAY!!

adruiz01 · Aug 4, 2009

I had a TB test last Tuesday, and a nurse told me I was negative for it on Thursday. However, it's been about a week and the redness is still there, and the area of injection is still slightly raised (very slight). Is this normal, and if so, how long does it take to go away?

I have no clue if thats normal, i dont know much about TB's besides the basic stuff. . .you should def post a new thread though so that everyone can see it and you may be able to get better answers faster but Im sure your fine :)