Syphilis test results and odd interpretation by doctor

[deksman2]

Hello
I was treated for Secondary Syphilis last December 6th, 2013 with Doxycycline therapy (100mg 2x daily - each pill taken 12 hours apart for 14 days) due to shortage of Penicillin and suspected allergy to Penicillin.
My numbers before treatment were:
RPR (1:32)
TPHA (1>10240)

I was re-tested on April 7th 2014 (last Monday) with some additional tests conducted and the results were as following:
RPR reactive 1:16
FBA-ABS IgG reactive 1:320
FTA-ABS IgM nonreactive
TPHA reactive 1:1280

TPHA seems to have reduced by 8 fold, but RPR reduced by half only.
I told my dermatologist that the inability to achieve a 4 fold decrease on RPR 3 months after treatment was not considered a 'success', but she said that the results were slower to go down on RPR because I took Doxycycline instead of Penicillin, and that the nonreactivity of IgM was confirmation that the bacteria is inactive (which seems to be confirmed by my research, but its odd).
Granted, I also read that achieving 4 fold drop on RPR could take as much 400 days (and that if it is not achieved by then, then the treatment is considered to be a failure).

I've read on Pubmed that IgM is not considered a too reliable resource (if done on its own - in this case, it was done in addition to standard testing).
I also asked my dermatologist if it would be recommended to do one more round of antibiotics just in case, but she said it shouldn't be necessary and that I should come back after 6 months to get retested.

I was wondering... what does Penicillin allergy test entail?
I was thinking on doing it for the purpose of asking my GP to see if she would recommend 3 jabs Intra Muscularly (1 per week) or just 1 IM jab, and then re-test afterwards.

Also, I experienced some eye issues since starting treatment for Syphilis... namely, I see small bulbs of light that travel on the edge of my right eye vision when I blink (not always, but occasionally - the issue seems to go away after taking Zinc Picolinate 50mg however - no other changes in eye vision, etc.). I mentioned this to my dermatologist as a concern for a potential Neurosyphilis infection, but she said that this was more in line with the changes in eye-gel (which my research confirmed, but I also recall that Neurosyphilis might cause similar problems) and that even though I was in a Secondary Syphilis stage, we caught it on time (I mentioned to her recorded cases of Secondary Syphilis where it managed to also turn into Neurosyphilis, but she said these were very specific cases and that we shouldn't be looking for a needle in a haystack.
My eye examination didn't turn up anything other the ordinary.

While I do respect her findings, the problem is that they don't really mesh with how a large portion of other doctors around the world might interpret these results - then again, having a consensus is not an indication that people are correct and we understand that evidence is not proof and correlation is not proof of causation - but my test results seem to be 'all over the place' and don't mesh with other findings (which also doesn't have to mean its 'potentially problematic' because each person reacts differently).

1. Should I take these results to another dermatologist for a second opinion and see if they could confirm my dermatologists interpretation of the results?
2. How complicated is a Penicillin allergy test and would it require a stay in a hospital?

I'm going to my GP with the results today, but just wanted to post this to gauge your reactions as well.

[deksman2]

Yup... was doing some more thinking and it does appear my dermatologist might have been correct.
Certainly, there is peer-reviewed data that supports her conclusions.

[Vance2335]

1. No I think what you have been told is correct.
2. Don't know, out of the scope of this forum.