Unprotected anal/oral sex early February. Day 3 treated with azithro 1G and cefixime 800mg.  Day 12 treated with doxycycline 100mg BID 10 days. Week 6 treated with amox/clav 875/125 BID 7 days (unrelated).

Numerous symps x 2 months - constant headache/pressure, twitching in head, numb face, dry mouth. 12.5 weeks developed a sore on lip that I’m concerned was chancre and since developed a rash on trunk.   Have tested for HIV (4th gen) and syphilis (EIA) at 12 weeks but I’m concerned antibiotics interfered with syphilis screening and lip sore was primary chancre.

Any chance the 12 week syphilis EIA was a false negative due to antibiotic use?  Any chance symptoms are neurosyphilis not being detected by EIA? Is the HIV test fully conclusive.  Any other STIs that I need to be concerned about? Neurosyphilis is my biggest concern at the moment - is this a realistic possibility at all?

Sigh.  Your unwarranted, out of control anxiety is once again leading you down a rabbit hole.  If you had syphilis when symptoms were present, particularly a rash, your test would have been positive.  Further the antibiotics you have taken would have prevented syphilis (the cefixime) or cured syphilis, in the unlikely circumstance that you were even exposed to. much less infected with syphilis.  There is absolute no possible way that your syphilis test could have been falsely negative.  The idea that you might have undetected neurosyphilis is absolutely fanciful.  ---

Thank you for your response.  I appreciate that I am experiencing some anxiety; however, I am also experiencing real symptoms that I have not been able to get answers to.   I have xerostomia (diagnosed by oral pathologist) with no known cause.  I ended up in the ER a few days ago because of the head pain and numb face - quite frankly concerns were dismissed and was told there was no way I could have syphilis without a large sore on my penis (not true) and that I would have to wait six months for definitive hiv results.  With the misinformation received I have little faith in the care received which is why I turned to you experts.  Please understand I am only trying to determine cause of my symptoms so I can secure appropriate treatment/relief.  

You are worrying needlessly.  At 12 weeks, tests for syphilis would have been positive.  You need to look elsewhere for the cause of your symptoms and not waste your time pursuing the implausible possibility that they are due to syphilis.  ---