I had an encounter that I'm extremely worried about that was 31 days ago. I gave  unprotected oral sex to male who was in his 40's, no ejacuation in my mouth. I thought I was being safe as I asked his HIV status first and also if he was clean of STDs which he stated he was clean and HIV negative. 

Why I am worried, 28 days after the encounter I noticed a very small what feels to be raised line in the inside of my lip, literally right inside bottom lip close to the actual lips. I can't see anything unless I take a flashlight to it and it appears to look almost like a small "slit" with a tiny bit of white. This has been present for 3 days now, no change is appearence.  I wouldn't say it's painless but not painful unless I rub it with my finger. I'm freaking out that this may be syphilis. I do get bad dry lips and smoke cigs so I don't know if it just cracked a little inside. My questions are:

1. Does this sound like syphilis? Everything I've seen online looks pretty nasty, although I know syphilis can vary.

2. I'm married with a 6 month old child. I don't kiss him on the lips but do on his head and cheeks, could infect him or by kissing my wife?

3. I was just tested for HIV and syphilis 2 months ago and was negative, should I test again? I would like to avoid going through that again. This is my only time with another man.

Based on the available information, it seems unlikely your partner had syphilis. And if he had transmissible syphilis of the penis, you probably would have seen an abnormality. Your description of the bump inside your lip isn't typical for a chancre (syphilitic ulcer). It also came on too late:  although chancres can appear as late as 4 weeks after exposure, most show up in 10-20 days. However, you should watch it for another 2-3 days. If it clear up, or if it remains unchanged (i.e. doesn't grow and become an obvious open sore) that will make syphilis still less likely. But no matter what else happens, have a syphilis blood test in a couple of weeks, i.e. around 6 weeks after the exposure, which will be 2+ weeks after onset of the oral bump. At that time, a negative test result will be conclusive.

Those comments pretty well cover your specific questions, but to be explicit:

1) See above. Very unlikely syphilis, but I cannot yet be quite 100% certain about it. I would put the odds at under 1 in a thousand. 

2) Brief kissing, assuring your lips are dry, will be safe for your baby. As for your wife, assuming French kissing, she could be at risk. OTOH, the chance you have it is low enough that if I were in your situation, I would take the risk -- unless if you avoid such contact you think you can pull it off for 2 weeks until tested.

3. Unfortunately, I don't think you can get away without testing. The chance of a positive result is very low, so testing itself shouldn't make you anxious.

Let me know if anything isn't clear.

HHH, MD

Thank you for the speedy reply. One last question, until then I won't post until I report my test result. A few hours after the exposure I took 1000mg Pen VK and the same dosage the next day that I had left over from strep. I know this was not near the dosage but I figured I'd ask if that would make a difference.

I will report back in 2 weeks with hopefully a negative result.

The lesion still has not changed, I can't see it unless I stretch my lip. The skin all looks intact, just a small white spot on the skin that's smooth. I'm still planning on going to my PCP next week for evaluation and a test. I can't find anything that resembles this. I know only 2 follow up questions are permitted but if you can leave this open I will report back the results. Just wanted to give an update on it and see if it sounds more likely syphilis or not. Thanks again for the service on this site.

I wanted to return and let you know I did go see my PCP regarding my oral bump. He said he it was so small so he really didn't think it was anything, maybe a blocked duct or a cyst but looked nothing like Syphilis. He agreed to send off my blood just to make sure. The test was performed 1 day short of 6 weeks but my doctor said that it would show positive if I was infected and wouldn't need to re test if negative. Well they called today and sure enough you were right and it was negative.

Given that you agree with my doctor that one day shy of 6 weeks is okay for testing, I would like to give you a sincere thank you for everything you do here. You've helped me mellow out twice now and as much I have enjoyed our exchanges, I hope this is the last time you hear from me. If you feel my result is conclusive I will not have anymore questions and will move on with my life without worry.

Best wishes to you and your family.

Best wishes and stay safe.