Syphilis - Symptoms and Causes

Overview

Syphilis is a bacterial infection that spreads mainly through sexual contact. The infection starts with a typically painless sore that appears on the genitals, rectum, or mouth.

People get infected through direct contact with these sores. Pregnant women can transmit the infection to their babies during pregnancy, childbirth, and sometimes after breastfeeding.

Bacteria can remain inactive in the body for years without symptoms, but may reactivate later. Without proper treatment, syphilis can cause serious damage to vital organs, including the heart and brain, potentially becoming life-threatening.

Early syphilis can be successfully treated, often with:

A single penicillin injection
Alternative antibiotics for those with penicillin allergies

Prompt medical attention is essential when symptoms appear. All pregnant individuals should be tested for syphilis during their first prenatal visit to prevent transmission to the baby.

Signs of Syphilis

Early Stage

The first sign of syphilis is typically a small, painless sore called a chancre. This sore appears where the bacteria entered your body, usually about three weeks after contact.

Most people develop only one chancre, though some may have several. Many people don’t notice these sores, especially if they are hidden in the vagina or rectum. The chancre heals by itself within 3 to 6 weeks, even without treatment.

Second Stage

A rash may develop while the chancre is healing or a few weeks after it disappears. This rash:

Often doesn’t itch
Appears rough, with red or reddish-brown marks
Can be faint and hard to see
Usually starts on the trunk (chest, stomach, back, pelvis)
May spread to arms, legs, palms, and feet

Other symptoms during this stage include:

Wartlike sores in the mouth or genital area
Hair loss
Muscle aches
Fever
Sore throat
Feeling tired
Weight loss
Swollen lymph nodes

These symptoms may come and go for months or years if untreated.

Hidden Phase

Without treatment, syphilis enters a hidden phase with no visible symptoms. This quiet period can last for years.

You might not have any signs of illness, but the infection remains in your body. Some people stay in this phase without further problems, while others develop serious complications later.

Advanced Stage

If left untreated, 30–40% of people with syphilis develop complications years after the initial infection. During this advanced stage, the disease can damage many body systems, including:

Brain
Nerves
Eyes
Heart
Blood vessels
Liver
Bones and joints

These problems can appear many years after the original infection, if not treated properly.

Widespread Infection

At any stage, untreated syphilis can spread to the brain, spinal cord, eyes, and other organs. This spread can lead to serious or life-threatening health problems.

Organ System	Possible Complications
Nervous system	Memory problems, stroke, meningitis
Cardiovascular	Heart valve damage, aortic aneurysm
Sensory	Vision loss, hearing problems
Skeletal	Joint damage, bone pain

Infant Infection

Pregnant people with syphilis can pass the infection to their babies through the placenta or during birth. Some newborns with syphilis show no symptoms, but without quick treatment, babies might develop:

Skin sores and rashes
Fever
Yellowing of skin and eyes (jaundice)
Anemia (low red blood cells)
Enlarged liver and spleen
Runny or stuffed nose
Bone changes

Later problems can include deafness, tooth abnormalities, and a collapsed nasal bridge (saddle nose). Babies with syphilis may be born too early, or may not survive pregnancy or early infancy.

When to Get Medical Help

Contact a healthcare provider if you or your child have any unusual symptoms like sores, rashes, or discharge, especially in the genital area.

Get tested for syphilis if you:

Had sexual contact with someone who might have syphilis
Have another sexually transmitted infection, like HIV
Are pregnant
Have multiple sexual partners
Have unprotected sex

Early detection through testing is important since syphilis can cause serious health problems if left untreated. Regular screening is recommended for people at higher risk. With proper treatment, syphilis can be cured, especially when caught early.

Causes

Syphilis stems from an infection with the bacterium Treponema pallidum. This infection typically spreads through sexual contact with an infected person’s sores. The bacteria can enter the body in several ways:

Through sexual contact (vaginal, oral, or anal)
Via small cuts or abrasions in the skin
Through mucous membranes

The disease is most contagious during its primary and secondary stages. It may also spread during the early latent period, which occurs within the first year after infection.

Besides sexual transmission, syphilis can spread through:

Kissing or touching active sores on the lips, mouth, or other body parts
From mother to baby during pregnancy or childbirth
Sometimes, through breastfeeding

It’s important to know that syphilis cannot spread through casual contact. You won’t get syphilis from:

Using the same toilet or bathtub
Sharing clothing or eating utensils
Touching the same doorknobs
Swimming in the same pool or hot tub

Once treated and cured, syphilis doesn’t return on its own. However, a person can become infected again through contact with another infected person’s sores.

Risk Factors

Having syphilis becomes more likely in these situations:

Engaging in sex without protection
Having multiple sexual partners
Living with HIV

Men who have sex with men face a higher risk of syphilis infection. This increased risk partly stems from healthcare access barriers and less consistent condom use.

For some in this group, finding partners through social media apps has become another risk factor.

Health Risks and Problems

Minor Skin Issues

Without proper treatment, syphilis may cause small bumps called gummas to form on the skin, bones, liver, or other organs. These growths are rare and typically appear in late-stage syphilis.

Brain and Nerve Complications

Syphilis can seriously affect the brain, its protective coverings, and the spinal cord. People might experience:

Severe headaches
Stroke
Inflammation of brain tissue (meningitis)
Personality changes and confusion
Memory loss similar to dementia
Partial or complete paralysis
Sexual dysfunction
Problems controlling the bladder

Vision Issues

When syphilis spreads to the eyes (called ocular syphilis), it may cause:

Pain or redness in one or both eyes
Blurry or changed vision
Complete vision loss if left untreated

Hearing Problems

Syphilis that affects the ears (otosyphilis) can lead to:

Partial or complete hearing loss
Persistent ringing sounds (tinnitus)
Dizziness and balance problems (vertigo)

Cardiovascular Damage

The infection can harm the heart and blood vessels by:

Causing the aorta (main artery) to swell and bulge
Damaging heart valves
Weakening blood vessel walls

Higher HIV Risk

Genital sores from syphilis bleed easily, creating openings in the skin. This makes it much easier for HIV to enter the bloodstream during sexual contact, significantly increasing infection risk.

Pregnancy Risks

Pregnant women with syphilis can pass the infection to their unborn babies. This condition, called congenital syphilis, creates serious risks including:

Miscarriage
Stillbirth
Infant death shortly after birth
Lifelong health problems for surviving babies

Ways to Prevent Syphilis

Syphilis has no vaccine, but there are several effective ways to prevent its spread. Taking these steps can significantly reduce your risk of getting or passing on this infection.

The surest way to avoid syphilis is through abstinence. A long-term relationship with one uninfected partner who is only intimate with you offers good protection if you are sexually active.

Before starting a sexual relationship with someone new, both of you should get tested for syphilis and other STIs. Using latex condoms correctly can lower your risk, but remember they only work if they cover infected sores.

Other birth control methods don’t protect against syphilis. Be careful with alcohol and avoid illegal drugs. These substances can impair your judgment and lead to unsafe sexual choices.

For women, avoiding douching is important. Douching removes healthy bacteria from the vagina, which might increase your STI risk. If you’re breastfeeding and have syphilis sores on your breasts, take care to prevent transmission to your baby.

Continue to pump or hand-express milk from the affected breast until the soreness subsides. If your pump comes into contact with a sore, please discard any milk it collects.

Healthcare providers may prescribe doxycycline to prevent infections in high-risk groups, like men who have sex with men and transgender women. Taking it within 3 days of sexual activity can reduce infection risk.

Telling Partners About Exposure

If you test positive for syphilis, informing your sexual partners is crucial. This includes current partners and anyone you’ve been with in the past three months to one year. Partner notification helps stop the disease from spreading further.

Your local health department can help with this process in several ways:

They can contact your partners without revealing your identity
A health worker can be present when you tell your partners
You can choose to inform partners yourself

This free service not only limits syphilis spread but also helps those at risk get proper counseling and treatment. Since syphilis can infect a person multiple times, partner notification also reduces your risk of reinfection.

Testing During Pregnancy

Syphilis can manifest without displaying any noticeable symptoms. This makes it possible to be infected without knowing it. The infection can have serious, even fatal, effects on unborn babies.

For this reason, health officials strongly recommend that all pregnant people get tested for syphilis. Testing is typically done at the first prenatal visit. In areas with high syphilis rates, doctors may recommend additional tests later in pregnancy.

Syphilis – Symptoms and Causes