Is she taking any medicines/therapy like steroids (for allergy/asthma) as these could lead to innacurate results. Have your wife be tested on your country for TB because PPD is not always accurate. People who tend to put pressure on the test site will have a smaller blister, which would then lead for the result to be positive carrier of TB. If she is negative on the test done on your country, then the next time she'll be tested for PPD, don't put any pressure on the test site. If it swells bigger, then it's a good sign that she is not a carrier of TB.
Is she taking any medicines/therapy like steroids (for allergy/asthma) as these could lead to innacurate results. Have your wife be tested on your country for TB because PPD is not always accurate. People who tend to put pressure on the test site will have a smaller blister, which would then lead for the result to be positive carrier of TB. If she is negative on the test done on your country, then the next time she'll be tested for PPD, don't put any pressure on the test site. If it swells bigger, then it's a good sign that she is not a carrier of TB.
just my 2 cents...