Welcome to our Forum. I have a two part answer for you. First, the likelihood that your partner's visible bump was syphilis is very, very low. The lesion does not sound typical. The lesions of syphilis are classically a rash (multiple lesions) or a single open sore, neither of which fits the description your provide. In addition, syphilis is a remarkable uncommon disease. In the entire U.S, there will be fewer than 10,000 cases of syphilis in our population of 350 million and two thirds of those cases will be in men who have sex with men. I would bet a lot that the lesion that you mention was not syphilis.
Second, we do know that a single shot of 2.4 million units of penicillin will prevent syphilis if you were exposed (which I doubt).
My advice, do not worry. Your sex was condom protected. Your risk of having gotten syphilis from the exposure you mention is very, very low. If you came to my clinic, I would not give you penicillin. EWH
Ceftraixone is less well studied than penicillin for syphilis prevention but would probably have the same effect. In my opinion, you did not need the treatment you received. EWH
Thanks Doctor,
AS a quick follow up, I went in and saw my MD this morning and he gave a shot of Rocephin Ceftriaxone (1 g i.m.) as a preventative measure.
In your opinion, would do the same thing as the penicillin?
Thanks for your help.