[Question #10252] Unprotected cunnilingus and (canker) sore?

24 months ago

I reside in a developed city in Asia. Just a little over three weeks ago I gave unprotected oral sex (cunnilingus) to a masseuse. This was the first and only time I have performed cunnilingus. Just a little under three weeks later, I developed a sore underneath the left side of my tongue. It is a white spot that is kind of ovular shaped and painful when brushed against something such as my mouth or food. The pain is amplified if the sore comes into contact with salt/salty food. I understand that giving oral sex is relatively safe but not zero in terms of STDs and that syphillis is possible. I looked up pictures of chancres and they appear quite similar to canker sores, so it is difficult to diagnose visually. However, I know that chancres are not supposed to be painful, and I also seem to recall that I bit my mouth or tongue near the area (but not the exact location of the sore) - not sure if related. It seems more like a canker sore to me but I just wanted some peace of mind so could you let me know if chancres could be painful and whether this sore could be a chancre?

H. Hunter Handsfield, MD

24 months ago

Welcome back to the forum. Thank you for your continued confidence in our services.

Your other questions, four years ago, also reflected concerns about syphilis. As in our discussions back then, it is a very unlikely cause of your oral ulcer. It probably is indeed a canker sore and unrelated to the sexual exposure three weeks ago. As you say, chancres usually are not painful or sore to touch. That said, for generations syphilis has been called "the great imitator" -- i.e. atypical cases can suggest other medical conditions, increasing the chance of delayed diagnosis; so I cannot say with certainty it isn't a chancre of primary syphilis. You should have a blood test, although you might waiting a few days. The syphilis blood tests typically become positive around a week after appearance of a chancre. Once 7 days have passed since it appeared (or ideally 10 days), a negative test result -- which definitely is what you can expect -- will confirm it isn't syphilitic.

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

HHH, MD

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24 months ago

Thanks Dr. Handsfield. As you probably are well aware, this is a unique invaluable resource and in my opinion much needed for many people, so if you decide to stop providing such services, I hope that you find successors! Some follow up questions if I may:

1. I understand that the risk here is very unlikely, but knowing the circumstances what would your rough estimate be in terms of the percentage risk?

2. You mention that I should test 7 days *or ideally 10* after I noticed the sore. Could you elaborate whether I can rely on the 7 days test, or should I wait the full 10 days?

3. Could this sore be indicative of other STDs or is syphilis the only one I should be concerned of and test for? I had two other protected sexual exposures that were too recent for STD testing so at this point it would not make sense to conduct tests other than for the cunnilingus exposure described in my initial question.

4. If theoretically the sore underneath my tongue is a chancre, could I spread this by kissing my partner on the lips or sharing food and/or utensils? What if there was some inadvertent contact with my tongue during kissing? I will otherwise refrain from french kissing and sexual activity during this time but I have already kissed (and will probably continue) my partner on the lips.

5. Could you kindly keep this thread open for maybe two weeks more until after my test in case I have a final follow up question?

Thanks again.

H. Hunter Handsfield, MD

24 months ago

Thanks for your kind comments about the forum.

1. I would guess the odds you actually caught syphilis at under one chance in a million.

2. The data are not precise on this. Seven days probably is OK and 10 days definitely is.

3. Ulcers or other sores at sexually exposed sites can be herpes. However, initial oral herpes is very rare after cunnilingus, and you don't describe any of the other typical symptoms that would suggest herpes.

4. Yes. If your oral lesion is syphilis, it is highly infectious by kissing. However, syphilis is not spread by eating utensils and the like. But we have discussed the low chance it's syphilis. If I were in your situation, I would be continuing sex with my wife, including French kissing and oral sex.

Threads are open for two follow-up comments and replies or for 28 days, whichever comes first. So this one will remain open for four weeks. I look forward to hearing from you after your test. In the meantime, do your best to mellow out. There is no realistic chance you have syphilis and you can expect a negative test result.

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24 months ago

Dear Dr. HHH, thanks again for your advice. I ended up taking the syphilis test 14 days after discovering the sore. The test came back negative as you expected. I do have a few follow up questions however:

1) You mentioned that syphilis is *highly* infectious by kissing if the lesion was a chancre even if there is no direct contact with the lesion. I thought that kissing was virtually no risk for STD transmission, is that not the case if a chancre is present? Therefore, is syphilis a concern regarding kissing?

2) I had protected vaginal sex on two occasions, 21 days and 18 days respectively before the syphilis test. Is this too early for the syphilis test to cover those two encounters or is the negative result at least indicative of absence of syphilis from those encounters?

3) I understand that conducting a STD test once a year (I assume HIV, gonorrhea, chlamydia and syphilis tests are sufficient) in general is a good idea if one is sexually active. What about in terms of number of encouners, i.e. after how many protected vaginal sex encounters would you suggest testing?

4) Lastly, is it a good idea to get the HPV vaccine? I have heard that the vaccine is not recommended after age of 26.

Thanks for your time, helpful advice and for providing this invaluable service.

H. Hunter Handsfield, MD

24 months ago

1) Any direct contact with a chancre has a high chance of syphilis transmission. Kissing is low risk in general because oral syphilis sores are uncommon. But if a syphilitic lesion is present, transmission certainly can occur. However, it is unlikely your oral sore was a chancre and you probably do not have syphilis.

2) Yes: those negative syphilis tests make it very unlikely you had transmissible syphilis during these sexual exposures.

3) There is no standard interval for persons at risk to be tested for STDs. The more sexually active with potentially risky partners, the more often testing should be considered. It might be as often as every 3 months or no more than every couple of years. I cannot advise you in any more detail -- it depends not only on the number of sexual exposures or partners, but on how risky those partners are. For example, high-end escorts (low risk) or street walkers, brothel workers, etc (high risk). Whenever it is done, only the tests you list are normally recommended.

4) By age 26, most sexually active persons have already been infected with many of the HPV types covered by the vaccine, so there is low benefit from being immunized. But there are exceptions and you could be vaccinated if you wish. It's expensive but harmless.

That completes the two follow-up exchanges included with each question and so ends this thread. I hope the discussion has been helpful. Best wishes and stay safe.

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