Positive TB test

First of all, you do read the induration, not the redness.

Whether or not a TB test is positive depends on the person's medical and social history.

For almost all healthy individuals born in the United States, a TB test is positive at 15 mm.

If you've had a dirty needlestick, contact with someone with TB, a blood transfusion before 1985, or same sex partners then you are positive at 5.

If you have a history of cancer, diabetes or kidney failure, or you were born in Africa, the Caribbean, or Asia then you are positive at 10.

Induration is what they really look for, not redness. 10 sounds about right, but I don't administer them and don't really have the number in mind right now.

That's all I have to say about it really. I should get mine done soon.

I have to get a TB test here soon and have no clue what to expect? Is it painful or something? After they inject the stuff intradermally when do I go back to get it "read" and why the need for a booster a week later??

Thanks!

Mine usually sting a bit.

It's read in 48-72 hours.

The booster is called a two-step test. It's like a double check.