so about 11 hours ago i had my annual PPD skin test for my company, and i just now noticed that its looking a little pinkish and welted, about as big around as a nickel. i don't know too much about them, think i might have something to be concerned about or maybe just a common rash from having something injected under the skin? i'm mostly curious, i figure theres a reason theres a few days between the injection and the reading, and nothing to worry about at this point.
PPD tests
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JPINFV
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It takes 1-2 days for the reaction to form, hence reading it 2-3 days after the injection. When I got mine generally the first night it was large and red (since there's a big mass of protein right under the skin) and by the time I went to get it read there was generally nothing left.
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the only information the nurses gave us was a face sheet with a Hx... no Hx of TB, but there was COPD/Emphysema. they told us he had a positive reaction and didnt know if he had a chest xray because they just came on their shift and he was a new admit.... so thats all i know... Pt couldn't tell us :censored::censored::censored::censored: because he was about CAOx1...
The important thing is what did you do when they informed you of the positive reaction? Did you put on an N95 mask for the transport?
Was the patient symptomatic? What prompted the PPD to be done? Was that the reason for transport or was a positive reaction just mentioned as part of his history? Is there a possibility the patient was from or spent time in a country that gave the BCG vaccine? Also, it would be rare to find a nursing home that has an isolation room suitable for housing a TB patient.
Aidey
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It is normal for there to be some swelling and redness around the injection area, the problem is if it lasts or gets bigger. I developed an allergy to the PPD test last year. I get a huge, but flat, red spot on my arm that lasts for several days. I totally freaked out the first time it happened, so I understand your concerns.
JPINFV
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The thing with purified protein derivative (PPD) tests is that it isn't a "do you have TB" test. It's a "do you have a secondary immune response" test. If you're body has been exposed and you have memory B cells for TB then you will test positive. This is why patients who has had a vaccine test positive, it's because they've been exposed. Everyone who has had their vaccines have been exposed to measles, mumps, rubella, tetanus, and any other vaccines that you've gotten. Being vaccinated doesn't mean you can't be infected. It just means that you'll produce a stronger immune response faster since your body already knows what to be looking for and has cells ready to produce antibodies in a variety of flavors to it as well as activate other immune cells.
This is important for two reasons. A positive PPD test is not a positive test for TB. It also isn't a positive test for active TB. It's a great surveillance tool since it avoids all of the bad things of a chest x-ray. So cutting down on radiation exposure is a really good thing. The other reason why this is important is because immunocompromised patients may test negative (which is why they're threshold is 5 mm lesion compared to 10 for health care workers and 15 for everyone else) despite having TB. If you don't mount an immune response, you won't produce a skin reaction.
This is important for two reasons. A positive PPD test is not a positive test for TB. It also isn't a positive test for active TB. It's a great surveillance tool since it avoids all of the bad things of a chest x-ray. So cutting down on radiation exposure is a really good thing. The other reason why this is important is because immunocompromised patients may test negative (which is why they're threshold is 5 mm lesion compared to 10 for health care workers and 15 for everyone else) despite having TB. If you don't mount an immune response, you won't produce a skin reaction.
ok, i think i get it. i'm not so worried now.
and as for the incident: yes we were wearing our masks, though there may have been a minute or so coming out of the elevator that we didnt have them on yet being that we were told he was in his room with the door closed. Pt was coughing, but non-productive as far as i could tell, maybe what you'd expect from a mild cold. his test was recent, no Hx of TB. he could have spent time in another country, but he couldn't tell us and there wasn't any documentation of it.
we did pretty much as we were taught, gathered info and filled paperwork the way i have for the past 2 years. this isn't exactly my first rodeo, i was just caught off guard in this case. I'm not a complete idiot, only a partial one....
and as for the incident: yes we were wearing our masks, though there may have been a minute or so coming out of the elevator that we didnt have them on yet being that we were told he was in his room with the door closed. Pt was coughing, but non-productive as far as i could tell, maybe what you'd expect from a mild cold. his test was recent, no Hx of TB. he could have spent time in another country, but he couldn't tell us and there wasn't any documentation of it.
we did pretty much as we were taught, gathered info and filled paperwork the way i have for the past 2 years. this isn't exactly my first rodeo, i was just caught off guard in this case. I'm not a complete idiot, only a partial one....
mycrofft
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Cutting to the chase:
1. Inject 0.1 ml PPD intradermally. This raises a welt if you did it right.
2. Read it at 48 to 78 hrs. Theoretically there could be reactions before this, and a "positive" can be delayed (messed up immune response) or obvious afer 72hrs due to the degree of tissue death at the site. 48 to 72 hrs is the standard, a conventin based upon scientific observation.
3. The hallmark is some degree of erythema, but always a defined area of induration (firmness) or development of an ulcer or true blisters.
Many folks react to the chemicals in the injection and develop a red spot which can last for months. Not a "positive".
Yes, you can have TB for the rest of your life and never become clinically ill if the infection is a light load (very few organisms) and your body handles them...walls them off in their little tubercles. This doesn't happen if the strain is malevolent, you lack the genetic wherewithall to do it, or the infection exposure was high.
You can carry potentially infectious TB in areas of your body besides the lungs, test positive but never get to coughing (although the primary exposure probably will have a respiratory presentation). I've seen pts with tubercular meningitis, tuberculosis of the testicle, and in the hip.
In fact, fosslized remains of humans and other creatures have been found with lesions strongly resembling tubercular destruction of skeletal tissues.
1. Inject 0.1 ml PPD intradermally. This raises a welt if you did it right.
2. Read it at 48 to 78 hrs. Theoretically there could be reactions before this, and a "positive" can be delayed (messed up immune response) or obvious afer 72hrs due to the degree of tissue death at the site. 48 to 72 hrs is the standard, a conventin based upon scientific observation.
3. The hallmark is some degree of erythema, but always a defined area of induration (firmness) or development of an ulcer or true blisters.
Many folks react to the chemicals in the injection and develop a red spot which can last for months. Not a "positive".
Yes, you can have TB for the rest of your life and never become clinically ill if the infection is a light load (very few organisms) and your body handles them...walls them off in their little tubercles. This doesn't happen if the strain is malevolent, you lack the genetic wherewithall to do it, or the infection exposure was high.
You can carry potentially infectious TB in areas of your body besides the lungs, test positive but never get to coughing (although the primary exposure probably will have a respiratory presentation). I've seen pts with tubercular meningitis, tuberculosis of the testicle, and in the hip.
In fact, fosslized remains of humans and other creatures have been found with lesions strongly resembling tubercular destruction of skeletal tissues.