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Old 11-01-2012
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Bacteria PPD Negative after TB Exposure; Treat or not?

A 3 year old kid who has been exposed to a confirmed case of TB presents to the Doc with generalized malaise. If the PPD test is done and it comes out as negative, will be give him Izoniazid then also??
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Old 11-01-2012
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3 year old child has high risk for severe form on tuberculosis. So contact should be treated even if PPD is negative and PPD to repeat after 8 - 10 weeks
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Old 11-01-2012
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Because children younger than five years are more susceptible to tuberculosis disease and more vulnerable to invasive, fatal forms of tuberculosis disease, they are assigned a high priority as contacts and should receive a full diagnostic medical evaluation, including chest radiography. If an initial skin test induration diameter is less than 5 mm and the interval since last exposure is less than eight weeks, treatment for presumptive M. tuberculosis infection (i.e., window prophylaxis) is recommended after tuberculosis disease has been excluded by medical examination. After a second skin test administered eight to 10 weeks postexposure, the decision to treat is reconsidered. If the second test result is negative, treatment should be discontinued and the child, if healthy, should be discharged from medical supervision. If the second result is positive, the full course of treatment for latent M. tuberculosis infection should be completed.
here
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Old 11-01-2012
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Originally Posted by gagan View Post
A 3 year old kid who has been exposed to a confirmed case of TB presents to the Doc with generalized malaise. If the PPD test is done and it comes out as negative, will be give him Izoniazid then also??
NO he wont be given INH, first because you dont give INH to PPD negative patients, also we have to define "exposure" was he in the room for 1 hour? 2 hours? 3 months?

You have to learn the PPD algorithm and how to proceed

Assuming you want to label this kid as "at risk" then a positive PPD would be greater than 10 mm of induration.

If you have a positive PPD you have to follow it with a chest X-ray, which if it comes back negative then you are labeled as a TB carrier and then you get INH for 9 months along with Pyridoxine

IF it shows cavitations then you obviously have Active TB and start the proper treatment.
if you have a negative PPD but a strong suspicion then you repeat the PPD, if the second one comes back as positive then you follow up with chest x-ray and ignore the first PPD because it is considered a False negative.

IN the END the US really wants to get rid of TB, so all people at risk are labeled as: You have TB until proven otherwise.
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Old 11-01-2012
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I believe it depends on the clinical suspicion. If the clinician has a high index of suspicion despite a negative PPD especially the duration since exposure has been short (not enough time for seroconversion) than you start prophylaxis till there is confirmation ( + or - PPD after 8-10 weeks) as very well explained by cingulate.gyrus.

So, basically, you give INH if in doubt until the PPD becomes positive due to exposure or by giving multiple PPD's !
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