QUESTION
Why on the STD Risks Chart is herpes the only STD listed that can be contracted from giving oral sex to a woman? Syphilis should be there. Since it's the sore that transmits the bacteria, not ejaculate, it shouldn't matter what body part it comes from. Am I right?

ANSWER
Yes, you are correct. We try to put the risk into the epidemiologic context, i.e., how frequent an STD is seen in the community. Fortunately, syphilis is extremely rare in women and heterosexual men currently in San Francisco, so statistically speaking, syphilis transmission is not likely through oral sex performed on a woman.

But yes, you are technically correct: A woman could have a vaginal chancre that could spread syphilis to another person’s tongue, mouth, etc. and vice versa: A partner could have a lesion on the tongue that could spread syphilis to the vagina during oral sex.

To your health,
Dr. K