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Date of last update: 8/21/2017.

Forum Name: Rheumatology Topics

Question: Positive ANA test... Negative retest. Very confused.

 DinoMartinez3 - Fri Jan 23, 2009 2:03 pm

Hello. I am a 20 yr old female and have a quick question. At school about two months ago, i got a bug bite (probably mosquito) on my foot, and it started itching terribly. I began to scratch it and saw a little bite mark and figured it was just a normal mosquito bite. Soon, it began to swell up and there was quite some inflammation. The next day, the swelling had reached my ankle and i went to my doctor. He performed an ANA test and it came out positive. He said that this might have been due to the infection/ inflammation from the bite, so he retested after the swelling went down, and it came out negative. What does this mean? Is it posible for ANA to come out positive from the type of infection that was on my foot? ANy help would be EXTREMELY appreciated. :)
 John Kenyon, CNA - Fri Jan 30, 2009 1:02 am

User avatar Hi there -

While many -- perhaps most -- medical tests can have a false negative but rarely a false positive, there are some that have the opposite problem, and ANA testing is one of those, mainly because it's not designed to uncover a specific disease or condition. The fact that you had an acute inflammatory process going on in your body (specifically your foot) when the test was done very likely threw the result off. Now that that's resolved you're coming up negative. It seems entirely likely the test was positive because of the rather severe reaction you'd had.

Hope this answers your question. Good luck to you. Follow up here as needed.
 DinoMartinez3 - Sat Jan 31, 2009 1:09 pm

Thank you so much for the response, John.

I've been extremely worried for the past few months as to what that result meant. I've been driving myself CRAZY and just want to forget about it! again, thanks for the response :) i really do hope that it was just because of the acute inflammatory response to the bite.

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