What should you know about syphilis from oral sex?

Syphilis spreads through direct contact with an infectious sore or rash during sexual contact. A sore may be painless and hidden inside the mouth, on the genitals, around the anus, or under hair, making it easy to miss. Kissing alone is not the usual route, but contact with a syphilis sore around the mouth can transmit infection. Condoms and dental dams can reduce contact with affected areas, although uncovered skin can still be exposed.

Book a confidential STI assessment if a partner has syphilis, you notice a mouth or genital sore, or you had oral sex with a partner whose status is unknown and feel concerned. Tell the clinician the type and timing of contact, where symptoms appeared, and whether a partner has been diagnosed. Testing commonly includes a blood test; a clinician may also assess a visible sore. Do not self-treat with leftover antibiotics. If diagnosed, complete the prescribed course and follow the advice about partner notification and sexual contact.

Arrange prompt care for a painless mouth, genital, or anal sore, a rash involving the palms or soles, or swollen glands after sexual contact. Seek urgent care for eye symptoms, hearing changes, severe headache, confusion, weakness, or problems with balance. If you are pregnant or might be pregnant, request prompt STI testing because untreated syphilis can affect a developing baby.

Which tests fit the timing of my exposure? Could a mouth sore be sampled? Should I avoid oral, vaginal, or anal sex until results or treatment are complete? Do partners need testing or treatment?