HELP! TB test positive after 14 hours?

PedsRN2016 · Jun 3, 2014

somuchdebt said:
Has anyone ever had a test that was positive in the first 24 hours that became negative after a while? I'm hoping it goes away in the next 60ish hours. Really panicking here, this is my dream job and I really don't want to screw it up

I can pretty much guarantee you that others are going to quote the Terms of Service that we can't give medical advice! Definitely consult your physician if you are concerned. HOWEVER, if it helps, here is MY TB test experience that I hope can't be equated to medical advice. Every time I get a TB test, I get the bleb and it goes away as planned. About 3-4 hours later, I get a large red area of induration that is more than 15 mm. By the time the test is read, the induration has completely flattened (though redness sometimes lingers) and my test is considered negative. I do usually spend at least a bit of time freaking out that I am going to have to deal with the fun that comes with a positive TB test. I obviously cannot reiterate enough that you should speak with your physician if you have concerns.

JustBeachyNurse, LPN · Jun 3, 2014

There is a reason the test isn't read until 48-72 hours post test. Any reaction prior to 48hrs is inaccurate.

I get a hive within 4 hours of the test. Every. Single. Time. For the past 15 years ago when the formulation was changed.

A bleb or hive/welt is not a positive reaction. Only an induration under the skin (to me it feels like a peanut under the skin)

BusyBee91 · Jun 3, 2014

Anecdote: I have a friend who has a reaction to the skin test but doesn't have anything show up on her chest X-ray or blood work. You may just have sensitive skin. Don't panic, let the professionals do their job and read it when appropriate. :)

meanmaryjean, DNP, RN · Jun 3, 2014

As JustBeachy said: There's a REASON why they aren't read for 48-72 hours.

nurse4ever08 · Jun 3, 2014

TOS for medical advice. Also it is read after 2 days. Some people do have allergic reactions. There are different brands of the test. Follow potential employer policy as well.

classicdame, MSN, EdD · Jun 4, 2014

best to know for sure. Talk to a pro

nurseprnRN, BSN, RN · Jun 4, 2014

Stop panicking. There's no need for that.

As one infectious disease doc told me, anybody who rides public transportation will have a positive TB test. This means that if you breathe air with enough people, it's a pretty safe bet that you will, eventually, inhale the tuberculosis bacillus, and if you have a normal immune system, you will make antibodies for it, the evidence for which is the positive skin test.

I agree you have to wait for the recommended time to have it read, but even if it is positive then, remember that. A positive skin test will not "screw up" a job interview, else half the nursing staff in city hospitals would be out of work. ?

amoLucia · Jun 5, 2014

GrnTea said:
Stop panicking. There's no need for that.
A positive skin test will not "screw up" a job interview, else half the nursing staff in city hospitals would be out of work. ?

This is esp true for Correction Officers too.

Cuddleswithpuddles · Jun 5, 2014

GrnTea said:
Stop panicking. There's no need for that.
As one infectious disease doc told me, anybody who rides public transportation will have a positive TB test. This means that if you breathe air with enough people, it's a pretty safe bet that you will, eventually, inhale the tuberculosis bacillus, and if you have a normal immune system, you will make antibodies for it, the evidence for which is the positive skin test.
I agree you have to wait for the recommended time to have it read, but even if it is positive then, remember that. A positive skin test will not "screw up" a job interview, else half the nursing staff in city hospitals would be out of work. ?

Huh, interesting!

Totally TOTALLY unscientific musing follows:

For the first few years of my yearly TB skin tests, I always had a gnarly looking "reaction" after the first day. These was during the time when I took the bus regularly. I always thought this was faint legacy of my BCG vaccination in the Philippines. Now that I no longer take the bus, I do not have these "reactions.

I will have to pick the brain of our ID doc!

KatieMI, BSN, MSN, RN · Jun 5, 2014

Your ID doc will just have to order Quantiferon Gold. That's another TB exposure test; it requires IV draw but gives "yes" or "no" answer with better specificity and it doesn't reflect BCG in the past.

It is a well-known fact that, although real allergy on components of Ppd (if it is manufactured and stored under supposed conditions) is so rare that it is almost a case of urban legend, pseudo-allergy on remnants of phenol (used in conservation of the protein reactive) is common, and activity of T-system (which is, basically, tested by Ppd) is easily and unpredictably affected by virtually everything in our existence. For example, a 1st degree sunburn can cause T-lymphocytes functions' suppression for up to 2 weeks and significant enough to affect immunotherapy, and detectable changes in baseline T- cell functional tests can be seen after female patient having unprotected sexual contact with "new" male partner as reaction of her immune system on massive "foreign" exposure.

The baseline is, some people can have atypical reaction on Ppd, just like on any other test or medicine, and we just don't know why. There can be gazillion of reasons, but as only one of them (i.e. infection with TB) has any practical importance, then there are two things to do: Quantiferon and/or chest Xray.

Meriwhen, ASN, BSN, MSN, RN · Jun 5, 2014

SoonToBeNurse2013 said:
I can pretty much guarantee you that others are going to quote the Terms of Service that we can't give medical advice! Definitely consult your physician if you are concerned.

And if I didn't quote it, I would get sacked from this place ?

So yes, OP: per our TOS, we can't give you medical advice. That is what your healthcare provider is for, and that is who you should direct your concerns to for the most accurate answers.

Though to help calm you down a bit...

As I'm placing the test, I tell my patients to ignore whatever is going on with the wheal for the next 48 hours because it's going to go through all sorts of changes. In fact, my own PPDs go through several frightening changes before settling down into their usual negative-reading state. I remind the patients that an accurate reading can only happen after 48 hours (and to be honest, closer to 72 hours is better).

Also, a positive PPD isn't necessarily a career-killer, nor does it mean you have active TB. With regards to the career aspect, your employer will usually do a follow-up chest-xray and as long as that is clear, you're good to go. I went to school with someone who had a positive PPD before admission: she has to provide occasional x-rays, but she's been working as a nurse for several years now.

As far as whether a positive PPD means you have active TB...again, that's out of our scope: only your HCP can answer that.

Relax...well, try to. And best of luck with everything.