[Question #7681] Latent Syphilis Testing

2 months ago

About 18  years ago I was a traveling musician and had a severe drinking problem. I was very promiscuous. Had unprotected and protected sex with different females almost daily. Received oral sex from males just as much. Nothing more than that. I know my behavior  put me in the high risk category for STD's.


One morning I noticed a big pimple/blister on the glans if my penis. Looked almost green/grey/yellow. I don't remember it becoming an open sore. Don't remember if it went away in a matter of days or if it stayed long. I'm more inclined to say it went away in days instead of weeks. I stupidly didn't go to the clinic and get it checked out. I put it out of mind. I finally got clean and haven't had a drink for over a year. Thinking of past mistakes now.


About a month  ago I had bad vertigo for about four days. So I started thinking maybe what I saw was a chancre.  Maybe I got Neurosyphilis or Tertiary Syphilis now. I got tested for Syphilis with one of those home std test kits. Everlywell.com it was. I tested negative. I've emailed them to ask what type of test they ran. Still haven't received the name of the specific test they ran. The response I got was, "The lab that processes our Syphilis Test screens for the Treponemal Antibody first (direct antibody for the organism that causes Syphilis). Then, a RPR (rapid plasma reagin) and titer test is conducted as the confirmation." Their website says they use the same labs doctor offices use. CLIA-Certified. 


I've read that long standing Syphilis can show negative on tests. The negative test hasn't done much to ease my nerves because of that. What test do  you recommend for someone like me? If I'm already on the late latent stage, or perhaps even worse, Neuro or tertiary, will a regular blood test suffice? When I get the specific test name I will update my post. 


H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
2 months ago
Welcome to the forum. Thanks for your confidence in our services.

You needn't be worried at all. For sure you do not have syphilis and never have, including neurosyphilis. The penile sore doesn't sound like syphilis; chancres do not appear as pimples or blisters. But most important, the blood tests you had recently are conclusive. You were tested according to the "reverse algorithm" -- that's what syphilis experts call the sequence of starting with a treponemal antibody test, followed by RPR if the initial test is positive. (As implied by the terminology, the traditional algorithm starts with RPR, followed by a treponemal antibody test.) While it is true that some tests miss syphilis, that applies only to the nontrepoenal tests, i.e. RPR and its cousin, the VDRL test. Indeed, this is one reason the reverse algorithm has been adopted by most labs:  starting with RPR has more potential for missing cases that need further evaluation and treatment. Your negative treponemal test is 100% evidence against syphilis currently or at any time in the past. (No need to look up the name of that test -- there are several, but all are equally accurate.)

As noted above, your penile lesion all those years ago clearly wasn't a chancre -- both from your description and you negative current test results. The most common overall cause of penile blisters is herpes -- but a single large lesion like you describe is very atypical for herpes. If you were taking any new medications at the time, I would wonder about the kind of allergic reaction called fixed drug eruption, which commonly occurs ion the genitals. But some sort of superficial infection (non STD) could have occurred. In any case, for sure it wasn't syphilis.

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

HHH, MD
---
2 months ago

Thank you for the info. The test I had was an FTA test. I have some follow up questions.


1.Would an FTA test catch a Syphilis infection from 20 years ago?


2. Would antibodies be present in this type of test even if I took Doxycycline for another skin disorder?

The reason I ask is because I've read Doxycycline is used to treat latent Syphilis. About three years ago I was on it for about 45 days to treat cystic acne. Twice a day 100mg I believe it was.

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
2 months ago
1,2) Once positive, the FTA test is positive for life, and remains positive even when syphilis is successfully treated (with doxycycline, penicillin, or anything else). This negative result is conclusive proof you never had syphilis, regardless of doxycycline or any other antibiotics you may have taken over the years..

---
---