PPD Question

[dizzyray822]

I know there are MANY questions about ppd results here but I thought I'd post mine too. I had it done today and the area looks irritated and is a bit itchy and slightly raised, not hard but slightly raised. I have extremely sensitive skin so I am thinking its just irritated from the injection right now. If I remember correctly it was the same last year when I had it done and they read it as negative even though it looked a tiny bit raised to me. What do you all think? I go Sunday for the reading, but just thought Id get some input here. Thanks!

[LA♥Nurse]

you measure the area of induration not the reddened area

Induration 5mm or greater - possible recent exposure

Induration 10mm or greater - possible active infection

[CorpsmanRN, BSN, RN]

As with the last responder, read the induration only. The CDC website gives info about what a "positive" induration is because it can depend on the circumstance (you might have to look under TB info for providers vs general pop info). Anywhere from a 5 to (I think) 15mm induration can be positive - for ex a person who was in contact with active TB, a 5mm would be Pos. where as someone who has had no risk factors would be Pos (or more likely a PPD converter) at 10-15mm.

As far as reading the induration, I was taught to use a ball point pen (at the 48-72hrs reading). You lightly roll the pen from the outer part of the test site towards the center. If there is an induration, the pen will/should stop as it bumps up against it (hence holding the pen lightly to the skin). Then you do the same to the opposite side. If you have 2 points where the pen stops, you read the mm's between each point, does that make sense? Since the induration can be hard to see without including the redness, this method has worked well for me. It is definitely possible you do have a little rxn at the site, but will likely subside & not be a "positive".

Hope that helps :)