Hello--Thank you for the service that you provide, and for taking the time to answer my question.

I am a man, and recently had two encounters with other men. They both consisted of brief exchange of unprotected oral sex, and brief mutual masturbation. Both men seemed trustworthy. They insisted that they were healthy and STD-free. One of them said that he was recently tested.

38 days after the first encounter, and three days after the second, I noticed a small canker sore on my gum. It has a white center, and the gums around it appear slightly reddened. On the previous night, I was out drinking, which I know can often cause canker sores. It was slightly painful and sensitive to the touch. I am now at two days after first observing the canker sore. It appears less inflamed.

Should I have any concern that the canker sore is indicative of syphilis or any other STD?

Thank you.

The exposures were low risk for syphilis, and 38 days is late for a chancre from the first exposure and 3 days much too soon for the second. It can take up to 6 weeks, but you're close. And if it is a typical canker sore (white base, painful), that also argues against syphilis (usually painless, not likely to be white). Further, chancres do not start to heal sooner than a couple of weeks, so improvement within a couple days is additional evidence. However, syphilitic chancres can be atypical, so I can't give complete assurance. However, in only a few days you'll be 6 weeks after the first exposure, which is sufficient for a reliable syphilis blood test. I would expect it to be negative. And you could then consider another test in a few weeks to be confident about the second exposure.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Dr. Handsfield,

Thank you very much for the quick and informative reply. I have one additional question. Last night, my ex-girlfriend texted me. We made plans to see each other tomorrow. If out history is any indication, things could become intimate. Is it safe to engage in sexual activity? 

Thanks, again!

Dr. Handsfield,

A quick update: The canker sore is not barely visible. I have to stand as close to the mirror as possible with a flashlight to even see the outline. It is almost completely healed.

Dr. Handsfield,

Thank you for your thoughtful and thorough replies. You've provided me with a great sense of relief. I would not hesitate to recommend your service to anyone in need.

Have a great weekend!