Trust in Syphilis test

Dear Doctor!
I´m a man from Scandinavia who stupidly, outside my marriage, once gave a brief unprotected fellatio without ejaculation to an unknown man in an adult club. I asked before we did it and he said he was “clean” from STD:s.  I still got tested for Chlamydia and Gonorrea 10 days after the event and I tested for HIV and Syphilis (VDRL) at 5 weeks after and again at 8 weeks ( 55 days). All tests came back negative. I haven´t noticed any chancre in my mouth and I have no “typical” symptoms of secondary Syphilis. However, knowing that there´s many exceptions from the typical symptoms of secondary stage I still worries about one single red spot on the side of my foot and some other pimple like rashes on my upper leg. I think the “pimples” were there before but I´m not 100 % sure of it. I have a little irritation in my throat as well but it has been there almost during the whole period so that might exclude syphilis.

My health care provider gives different message depending on who you ask regarding the need of further testing. Some says 12 weeks follow up and some 8. I trust 8 weeks regarding HIV but when it comes to Syphilis they seem less confident. Calling for a new appointment I got the information that it wasn´t necessary.

I read your answers to other worried people and you seem very confident that a test after 8 weeks like mine is conclusive without worries of false negative. Can you help me trust my result by answer the following;

- It´s said that a syphilis blood test always turns positive within 6 weeks follow the exposure but why is it so common with a recommendation of a 12 weeks follow up? Has there been any new knowledge the past few years changing previous recommendation?

- Is VDRL as reliable as RPR?

- Do you think the symptoms I describe give any reason to persist in getting a further test done or can I really leave the worries of Syphilis behind me?

Best regards and thanks!

[Edward W Hook, MD]

The combination of the lack of lesions and two negative blood tests is solid, totally believable evidence that you do not have syphilis.  For you to continue to be concerned about a disease for which you are at low risk because it is so very rare and for which the tests are so good is more a manifestation of your anxiety over the exposure you describe than a realistic possibility.  Believe your results.

the RP{R is just as reliable as the VDRL.

You do not need further testing.  EWH

[Jurgen40]

Thanks for your answer. It´s very confident and it will help me get over the anxiety.

Since english is not my mother toung I might misunderstand the term "lesions". May I ask if you by "lack of lesions" mean that I didn´t have an obvious primary sore in my mouth?

Is the symptoms I described of suspected secondary stage not considered to be lesions?

[Edward W Hook, MD]

By lesions I meant sores.  The problem with trying to attribute your pimples to syphilis is thathtere are so many causes of pimples that unless your pimples are accompanied by a positive syphilis test, you cannot attribute them to secondary syphilis.  I repeat, secondary syphilis is very, very rare.  There really is no reason for you to be concnerned.  EWH