Syphilis: Symptoms, Causes, Risks, Complications, Diagnosis, Treatment and Prevention

Illustration of Syphilis


The number of sexually transmitted diseases (STDs) has increased drastically over the past years. In fact, three of the most common types of STDs increased in the United States since 2006. In the latest report from 2014 by the Centers for Disease Control and Prevention (CDC), more than 1.4 million cases of chlamydia were reported. Also, the cases of syphilis increased to 20,000 and gonorrhea to about 350,000.

Syphilis cases increased among homosexual and bisexual men. Despite the fact that the increase of cases in males and females was 15.1 percent, men who have sex with men account for approximately 90 percent of new cases.

Syphilis is a sexually transmitted disease caused by Treponema pallidum, a type of bacteria. This is typically transmitted through sexual contact and it begins as a sore (painless) on the genitals, mouth or rectum.

After being infected, the bacteria can become dormant inside the body for many years before becoming active again. The good thing is, this is a curable disease but without treatment, it may lead to serious complications and can be potentially fatal.


Syphilis is categorized into three stages. Each stage has its own set of symptoms.
In some cases, however, there can be no signs or symptoms even for many years.

Primary syphilis

The primary sign of syphilis is the development of a painless, round and firm sores called chancre. These chancres disappear between 3 and 6 weeks. Though the disease may go on to the second stage if it’s not treated.

Secondary syphilis

During the second stage of the disease, the patient will experience a sore throat and skin rashes. The rash is not itchy and usually found on the palms and soles. The symptoms of this stage include headaches, fatigue, fever, swollen lymph glands, hair loss, joint pain and weight loss. Usually, this stage of syphilis is often seen as another condition and they may go away again even without treatment.

Latent syphilis

If the patient is not treated for syphilis, the infection travels from the second stage to the latent or hidden stage. The latent stage may last for many years without any symptom. However, when this stage is not detected and the infection is not treated, it might move to the late stage, which can be potentially fatal.

Tertiary or Late syphilis

Approximately 15 to 30 percent of patients with syphilis who do not get early treatment will develop certain complications in the late stage. During this phase, the disease may harm the nerves, brain, eyes, heart, liver, bones, joints, blood vessel and the heart.

Congenital syphilis

Babies who were born to mothers with syphilis may become infected during pregnancy or during childbirth. Most infants with this infection may have no symptoms at all. However, some may develop a rash on their soles and palms. When it’s not treated, it may lead to a saddle nose, deafness, and some teeth deformities. In the late stage, there can be:

  • Gummas or soft tissue inflammation that may develop anywhere in the body
  • Organ damage


Neurosyphilis is a condition where the bacteria has already spread to the nervous system. It is linked to latent and tertiary syphilis. The symptoms may not appear early and can develop gradually in time. The symptoms of this condition include:

  • Abnormal gait
  • Numbness particularly in the extremities
  • Dementia
  • Altered mental status
  • Confusion
  • Headache
  • Seizures
  • Difficulty in concentration
  • Vision loss or problems
  • Weakness


A bacteria called Treponema pallidum causes syphilis and the most common way of transmission is through contact with an infected individual chancre during sex. The bacteria will then enter the body via small wounds, abrasions, and cuts in the skin or mucous membranes. This condition is infectious during the primary and secondary stages.
In some case, people at the latent stage of the disease can also transmit the bacteria, especially if there is a chanre.

Rarely, syphilis may also spread through direct unprotected close contact with an active lesion like during kissing or from a mother to the baby during pregnancy or delivery.

Syphilis cannot be spread through shared contact with objects like toilet seats and doorknobs.

4Risk Factors

Some people are at a higher risk of contracting syphilis due to certain factors, such as:

  • People who engage in unprotected sex
  • People who have multiple sexual partners
  • Men who have sex with men
  • People infected with HIV, the virus that may lead to AIDS


Without treatment, syphilis can lead to damage in many parts of the body and it also may increase the risk of being infected with HIV. In women, it may lead to pregnancy problems. Here are the common complications of syphilis.

Tumors or small bumps

Without treatment, the infection may cause the appearance of gummas, which are small bumps that can develop on the skin, liver, bones and other organs in the body during the late stage of syphilis.

Cardiovascular problems

The bacteria may also cause cardiovascular problems like inflammation of the aorta, damage to the heart valves and bulging of the blood vessel called an aneurysm.

Neurological problems

Syphilis can cause many problems in the nervous system. The infection may lead to stroke, hearing loss, visual problems, dementia, stroke, meningitis, loss of pain and temperature sensations, impotence or sexual dysfunction, sudden and lightning-like pain, and bladder incontinence.

HIV Infection

Some people with sexually transmitted syphilis or other genital ulcers have a two-to-fivefold heightened risk of acquiring HIV infection. Syphilis sore may bleed easily, creating an easy way for HIV to enter the body.

It is also important to note that those with HIV infection may have several syphilis symptoms than those without the disease.

Pregnancy problems

For pregnant mothers, the virus can be transmitted to the unborn baby during pregnancy. Congenital syphilis may increase the risk of stillbirth, miscarriage, and death within a few days of life. It is important to undergo testing during pregnancy.

Congenital syphilis can be life-threatening with symptoms like liver inflammation, swelling of the spleen, seizures, deformities, developmental delays, rashes, fever, anemia, infectious sores, and jaundice.

If a baby with the condition is not treated immediately, it may develop to late-stage syphilis that can damage the eyes, ears, brain, teeth, and bones.


The doctor will conduct a physical examination and a medical history interview. The doctor will also ask about the patient’s sexual history to determine if he or she is at risk.
After the assessment, further tests are needed to confirm the diagnosis.

Blood test – Certain blood tests can detect a current or past infection. These are used to confirm the presence of antibodies that the body produces to battle infection. When there are antibodies against the bacteria that cause syphilis, it means that there is an ongoing or past infection.

Body fluids – The doctor can also ask for the testing of the fluid coming from the chancre during the primary and secondary stages of the infection.

Cerebrospinal fluid – The doctor may request for an analysis of the cerebrospinal fluid to determine if the bacteria has already reached the brain and has affected the nervous system. This sample can be acquired through a spinal tap or lumbar puncture.


When diagnosed and treated early, syphilis is very easy to cure.

Antibiotics for syphilis

The usual treatment used is penicillin. Penicillin is an antibiotic that can kill the bacteria.
A single injection of penicillin can already hinder the progression of the disease.This is recommended for people with syphilis for less than a year. However, for those who had the infection longer, additional doses might be needed.

This antibiotic is the only recommended treatment for pregnant women and those who have an allergy to the drug, they can undergo a desensitization procedure to allow them to take the medicine.

It is important for the disease to get treated early because it will not go away on its own.
If it’s left untreated, it may lead to serious complications. Also, the patient should finish the recommended dosage because if he or she will not, an antibiotic drug resistance may occur.

Monitoring and testing

After the treatment, the patient may need to be tested regularly to make sure the infection will not recur and the antibiotic treatment has been successful in eradicating the bacteria in the body. The patient may also need to visit the doctor regularly for consultations and monitoring of the disease and its progression. Being tested on a frequent basis is important to make sure the patient is not infectious anymore and the complications can be prevented.


Currently, there is no vaccine available for syphilis. To help prevent the spread of the disease, here are common preventive measures:

  • Use latex condom when having sex with your partner. However, condoms can be effective only if the area covered is where the sore is.
  • Abstain from sex or remain monogamous. One of the ways to avoid being infected is to forgo having sex. However, if you know your partner is monogamous, you can have sex. Maintain a mutually monogamous relationship.
  • Avoid recreational drugs like illicit drugs and alcohol that can cloud your judgment and lead to practicing unsafe sexual practices.