I'm sorry to be back here, I have been full of anxiety. I messaged previously about unprotected oral with a female. I mentioned in the last post that I kissed my partner on the lips 48 hours after exposure, my child also kissed me on the lips within the 5 days before I started taking doxycycline. Two and a half weeks later, my child has developed a painful yellow sore accompanied by cough and sneezing. He said his face hit a branch and a day or 2 later he noticed the sore. I'm still a couple of weeks out from testing for syphilis. I had no noticeable lesion on my lips at the time of kissing either my partner or my child. To add further I upped my dose from 100mg for 6 to 200mg for 10 days. I drank heavily for a few days over the course. I am beset with fear. I know you said syphilis can't be transmitted before 2 weeks, but I keep thinking that I'll be the exception, that I had a hidden lesion somewhere. I'm reaching out for your expertise. 

Welcome back to the Forum although I'm sorry you felt the need.  In preparing to respond I reviewed your recent interaction with Dr. Handsfield and agree with all that he said.  Your risk for syphilis, if there was any risk at all, was miniscule.  The symptoms you describe are likely due to some other non-STI process.  Cough and sneezing are not symptoms of syphilis.  Have you asked your pediatrician what is going on?  ---

Thank you for your response. I only stopped taking the doxycycline over a week ago. I read that I need to wait 4 weeks after last dose to test. The test will be an EIA test. When the time comes it will 8 weeks post exposure. If it were just me on my own I would not be anywhere near as concerned. If positive, as unlikely as you feel it'll be, I would of course disclose that she had an ulcer. But that frightens me. As for her ulcer it's responding well to topical gel if that helps. It has been there for just over a week now. Can transmission happen in such a short time frame, days after exposure, with no visible lesions?