[Question #1440] HIV Rapid Test Question and Accuracy

84 months ago
Hi Doctor,

9 weeks ago I had a risky encounter (night out drinking and lots of hooking up with a TS CSW but no intercourse). I had a rapid HIV blood test done today at Planned Parenthood here in the USA that came back negative. Almost 6 weeks after the encounter my skin started getting itchy. I started getting a red, flat rash. The rash (usually itchy/stingy) would be on my neck area for a few minutes and then disappear. Then, a few minutes later it would appear on another area of my body, like my chest. It would then disappear after a while and reappear on another area, like my hands or belly or pubic area. 

After a week of this, a dermatologist put me on a 16-day course of Prednisone (40mg X 4 days, 30mg X 4 days, 20mg X 4 days, 10mg X 4 days). He called it a maculopapular rash, although it appears pretty flat when I look at it. The rash is tricky in that it got better after a few days on the Prednisone and than flared up again on the Prednisone...got better and flared up a little again).

I finished the Prednisone this past Saturday morning (2 days ago, which is also 2 days before the HIV rapid blood test that I took today). The rash has been better for the past 3 days.  So basically, the timeline is that:

I had a risky encouner 9 weeks ago, got an itchy/stingy rash just shy of 6 weeks after the encounter, and then was on a high-dose 16-day course of Prednisone from about 7 weeks after the encounter until 2 days before my test. 

My questions are:
1) Is the negative HIV rapid blood test result that I got today accurate, considering I just finished a 16-day course of Prednisone 2 days ago?
2) Could the Prednisone have affected or masked my test results today?
3) Will I need to retest? If so, when?
4) At PPH today, a test for syphilis was done, which they said will also test for HIV and have results in a week.

Thank you very much for your help Doctor.

H. Hunter Handsfield, MD
84 months ago
Welcome to the forum. Thanks for your question.

My general comments are first that you had a low risk encounter, not a high risk one. I'm guessing "hooking up but no intercourse" meant you had oral sex, which is safe sex. There has never been a proved case of HIV transmission mouth to penis. There is avery small risk by performing fellatio, but even this calculates out to roughly one transmission for every 10,000 exposures. That's equivalent to performing BJs on infected males once daily for 27 years before transmission might be considered likely. (I'm assuming your trans parter is male to female trans but has not yet had sex reassignment surgery. If she has, the risk is even lower.)

Second, the blood tests for HIV, either rapid or lab based, are always conclusive more than 6+ weeks after exposure. (If it was a 4th generation, i.e. antigen-antibody test, it's conclusive at 4 weeks.) Finally, taking prednisone has no known effect on the timing or reliability of HIV testing. To your specific questions:

1-3) Your results are conclusive, the prednisone could have had no effect, and no further testing is needed.

4) You can expect the syphilis test to be negative, as will the repeat HIV test.

I hope this information has been helpful. Let me know if anything isn't clear.

Best wishes--  HHH, MD

83 months ago

Thank you very much for your reply and for your help. I'm not exactly sure which kind of tests I had done.  All I know is that one was the finger prick rapid test (I think by Clearview), and the other was drawn into a tube and then sent out to a lab. I'm not sure which generation they were or if they were antigen-antibody.

The only follow up question I have for clarification is that when you said," the prednisone could have had no effect" on the testing, does that mean the prednisone "maybe" had no effect? Or does it mean that the prednisone had no effect on the testing and that I can accept the negative result and move on?

Please forgive me if my anxiety is over analyzing words.  

Thank you very much.
H. Hunter Handsfield, MD
83 months ago
Sorry it wasnt clear. The second meaning. You had a relatively modest dose of prednisone, not high dose. Even in higher doses, prednisone has no effect on the body's ability to produce antibody, and no effect on the performance or reliability of any antibody tests for HIV or any other infection.

Probably both tests were modern (3rd generation antibody or 4th gen antigen-antibody), in which case the results are conclusive. If it was an older test (2nd generation), then a final test at 3 months could be considered. But even then, it rarely takes more than 8 weeks after exposure to be conclusive. If you would like to contact the doctor or lab and learn exactly what tests were done, I'd be happy to further confirm all is well.

And I stress again that nobody catches HIV by oral sex. You reallly didn't need testing at all on account of the exposure described.
83 months ago
Hi Doctor,

Thank you for replying again. The other test results have come back, and like you explained, they are negative. I'm not sure what everything means, but there are two different recordings:

HIV 1 and 2 AB and HIV P24, HIV Combo AG/AB EIA Negative

HIV Combo AG/AB EIA Non-Reactive, HIV 1 / HIV 2 Antibodies and HIV P24 antigen not detected

Also, the Syphilis test reads Non-Reactive

I'm pretty sure this is good news, and I just wanted to see if I can accept these test results as negative and conculsive.

Thanks very much for your time and all of your help.
H. Hunter Handsfield, MD
83 months ago
Indeed, those results are negative and conclusive.

Thanks for the thanks. Take care and stay safe.