Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. It spreads through direct contact with a syphilis sore, which mainly occurs during vaginal, anal or oral sex. While kissing alone does not transmit syphilis, open sores in the mouth can spread it through saliva.
Can you get syphilis from kissing?
Kissing itself does not transmit syphilis. The bacterium spreads through direct contact with syphilis sores, which are painless ulcers or lesions. These sores most commonly develop on the external genitals, vagina, anus or rectum. Less commonly, they can appear in the mouth or on the lips.
So while simply kissing someone on the lips does not spread syphilis, kissing someone with an active mouth sore can pass the bacteria through contact with the sore. The sore would also need to come into contact with a cut or break in the skin around the lips for transmission to occur.
What are the stages of syphilis?
Syphilis progresses through four stages if left untreated:
- Primary syphilis – Painless sores at the infection site (genitals, mouth, etc). Sores last 3-6 weeks.
- Secondary syphilis – Rash on the soles, palms, torso and other areas, along with fever, swollen lymph nodes and tiredness. Lasts 2-6 weeks.
- Latent syphilis – No symptoms as bacteria remain in the body. Early latent syphilis occurs within the first year after infection. Late latent syphilis occurs after the first year.
- Tertiary syphilis – Severe internal organ damage after many years, leading to organ failure and death.
The primary and secondary stages are when syphilis is most contagious. The painless sores allow the bacteria to easily spread through contact. After the sores heal, the infection enters the latent phases and is no longer contagious.
What are the symptoms of primary syphilis?
The primary stage of syphilis occurs 2-6 weeks after infection. Symptoms include:
- One or more small, painless sores at the infection site (genitals, mouth, lips, etc)
- Sores last 3-6 weeks before healing
- Swollen lymph nodes near the sore
Without treatment, sores will go away on their own after 3-6 weeks. However, the infection remains in the body and progresses to the secondary stage.
How soon after exposure do syphilis symptoms appear?
If syphilis symptoms are going to appear after exposure, they will develop within 10-90 days. However, the average incubation period is 21 days.
After initial exposure, here is the timeline for syphilis symptoms:
- 3 weeks – Primary sore appears at site of infection
- 6 weeks – Primary sore heals, secondary rash appears
- 6 months – Rash and symptoms clear as infection enters latent phase
Without treatment, syphilis can lay dormant for decades before reemerging in the dangerous tertiary stage. But with early treatment, the infection can be cured before reaching this point.
How long are you contagious with syphilis?
Syphilis is contagious during the primary and secondary stages, when symptoms are present. This includes the time when primary sores are present and for about 1-2 weeks after they heal.
Once the painless sore heals and the rash clears, syphilis enters the latent phase. At this point, it is no longer contagious.
So the total duration of infectiousness is:
- 3-6 weeks with primary sore present
- Plus up to 2 weeks after sore heals
- Total of about 2-8 weeks
Without treatment, syphilis can re-enter the contagious tertiary stage after many years. But proper antibiotics during the primary or secondary stages can prevent this.
Conclusion
Kissing alone does not transmit syphilis. However, kissing someone with an active mouth sore can spread the bacteria through the sore. Syphilis mainly spreads through unprotected vaginal, anal or oral sex with someone who has an active syphilis sore.
The stages when syphilis is contagious are the primary stage (with active sores) and secondary stage (with rash). The total duration of infectiousness is about 2-8 weeks if left untreated. But antibiotics during the primary or secondary stages can cure syphilis before the contagious tertiary stage develops years later.