What Does Positive Skin Test And Negative AFB Stain Mean?

Posted on Fri, 3 Jan 2014

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Fri, 3 Jan 2014 Answered on

Sat, 25 Jan 2014 Last reviewed on

Question : my skin test is positive but my afb stain is negative. what does that mean? what should I do?

Answered by Dr. Sudhir (1 hour later)

Brief Answer: These are test done for tuberculosis. Detailed Answer: Hello. Skin test is positive means you have antibodies against acid fast bacilli in your body, either due to vaccination, prior exposure without infection, prior healed infection or current infection.This positive test doesnt always mean you have the infection. AFB stain negative - means there was no actual acid fast bacilli in the sample which was tested.A positive result confirms infection.A negative results supports absence of infection but dosenot completely confirm that there is no infection as we have only tested small sample. Now your doctor with help of his/her clinical judgement will advice more investigations or look for other causes as well. Hope this helps.Please ask if there are any doubts.Regards.

Above answer was peer-reviewed by : Dr. Shanthi.E

Follow up: Dr. Sudhir (2 days later)

am I fit to work even if my skin test is positive but my afb stain is negative? do you think the internal medicine doctor will clear me?

Answered by Dr. Sudhir (2 hours later)

Brief Answer: Doctor might clear you Detailed Answer: Doctor might clear you depending on few things - severity/grade of skin reaction , few blood tests and chest xray .If these tests are fine doctor may clear you on basis of false positive test/reaction; I would clear you. Regards

Above answer was peer-reviewed by : Dr. Prasad