Can you Get Syphilis from Kissing?

Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum. If left untreated, syphilis can lead to serious and potentially life-threatening complications affecting the brain, heart, nerves, and other organs.

Because syphilis is a bacterial infection, it is curable with appropriate antibiotic treatment, especially when diagnosed early.

Syphilis spreads through direct contact with a syphilis sore (chancre). The bacteria enter the body through mucous membranes or small breaks in the skin.

Transmission most commonly occurs through:

• Vaginal sex

• Anal sex

• Oral sex

In some cases, syphilis can be transmitted through kissing if a chancre is present on or inside the mouth. Chancres are often painless and may go unnoticed, yet they are highly infectious.

Syphilis can also be passed from a pregnant person to their baby during pregnancy or childbirth, a condition known as congenital syphilis, which can cause severe complications or fetal loss.

As syphilis progresses, it develops in stages. Each stage has different symptoms and health risks, as detailed in the Call-On-Doc Guide to Syphilis.

Stage 1: Primary Syphilis

• Characterized by a painless sore (chancre) at the site of infection

• Symptoms usually appear about 21 days after exposure, but may range from 10 to 90 days

• The sore heals on its own, but the infection remains

Stage 2: Secondary Syphilis

• Occurs weeks to months after the initial sore

• Symptoms may include:

  • Skin rash (often on palms and soles)

  • Mucous membrane lesions

  • Fever, fatigue, sore throat

  • Swollen lymph nodes

• Symptoms may resolve without treatment, but the infection persists

Stage 3: Latent Syphilis

• No visible symptoms

• Can last for years or decades

• Infection remains active internally and can still cause damage

Stage 4: Tertiary Syphilis

• The most severe stage

• May develop 10–30 years after infection

• Can cause damage to the heart, brain, nerves, eyes, and other organs

• Requires urgent medical management and may result in permanent complications

Syphilis is treated with prescription antibiotics, most commonly penicillin, which is highly effective—especially in early stages. Prompt treatment prevents progression and long-term damage.

If syphilis has been present for an extended period without treatment, additional doses and close medical follow-up may be required. Delayed treatment increases the risk of serious complications.

Early testing and treatment offer the best outcomes.

Yes. While less common than sexual transmission, syphilis can be spread through kissing if an infectious sore is present in or around the mouth. Because oral chancres may not be visible or painful, people may unknowingly transmit the infection.

This makes testing especially important when entering a new relationship or if there is any uncertainty about a partner’s sexual health history.

Syphilis is preventable with:

• Consistent condom use

• Routine STI testing

• Limiting the number of sexual partners

• Prompt treatment of infected individuals

• Open communication about sexual health

Because symptoms may disappear on their own while infection remains active, testing—not symptoms—is the only reliable way to know your status.

Do not feel embarrassed or afraid to get tested. Syphilis is common, treatable, and curable, especially when diagnosed early. Taking action protects your health and the health of others.

With modern telehealth options, you can begin care discreetly online. While testing requires a lab visit, follow-up care and treatment guidance can often be handled virtually.

Call-On-Doc is a highly rated online provider for STD care. Get the testing and treatment you deserve—on your terms.

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