Almost certainly you don't have active syphilis and never did. In the very slim chance you have had it, there is no realistic chance it is active and will ever harm you and most likely nothing more need be done, except perhaps to monitor your blood test result (i.e., repeat RPR or other nontrponemal test) once a year. Beyond that I cannot help. And will not get into details of management. This is my last reply.
My doctor told me I have tested neg for Lupus a couple of months ago and I have been to old Soviet countries a few times in my teens (last time 4 years ago) but have never had anything that looked like yaws on my body. I really like to be on the safe side of things and will constantly think about this until it is solved 100% though so I have 2 more questions...
1. I am definitely going to retest in a couple of weeks, but if the results are like they were today, If I were to insist on getting penicillin treatment are there any possible side effects if I don't have/never had syphilis? By that I mean, can/will any real, dangerous or permanent negative damage be done to me at all assuming I'm not allergic?
2. I have read that syphilis can spread much more quickly in some than others to other areas of the body like the spinal fluid and cause many problems later on, and is conventionally not curable the same as regular syphilis. Is this true? Does a blood test rule out/diagnose this, or is a CSF exam 100% necessary to know for sure?
I know it's probably nothing but I rather invest a little time and work to be positive. Thanks very much.
Previously you had what seemed like a biological false positive test result, with no evidence of past syphilis. With the "slightly reactive" FTA-ABS, there is a slight chance you have had syphilis sometime. However, weakly reactive test results like that can occur in some people with various autoimmune diseases, like lupus erythematosis. Others are simply unexplained. There also might be a slight chance you have had yaws or pinta, which are due to bacteria very similar to Treponema pallidum, the cause of syphilis. Those diseases do not exist in the US, but could be a possibility if you have ever lived in south-central Europe (Bosnia, Croatia, Greece, etc) or parts of South America or Africa.
Still, since you are at low risk for STD, most likely you have never had syphilis or any of the other infections. If you did, the doxycycline probably would cure it. Or if you want to be definitively treated for possible syphilis, you could receive the standard penicillin regimen (injection once a week for 3 doses). But I doubt it is necessary.
Bottom line: You might never going to know for sure, and it probably doesn't matter; the chance of a serious health outcome is zero for practical purposes. But if you want to follow up further, ask your doc for referral to an infectious diseases specialists for a definitive, final determination and advice.
That's the best we can do on this forum. Best wishes--
HHH, MD