Syphilis: Types, Symptoms, Causes, and Diagnosis


You may have heard of syphilis, but many people are not sure what it is. Syphilis (SIFF-I-lis) is a sexually transmitted disease caused by bacteria that are passed sexually. It can infect the vagina, anus, urethra, or penis, as well as the lips and mouth. An infected pregnant woman can also pass the disease to her unborn child.

Syphilis is not spread by contact with toilet seats, doorknobs, swimming pools, hot tubs, bathtubs, shared clothing, or eating utensils.

Syphilis rates in the United States have been declining among women since 2010, but rising among men, particularly men who have sex with men. The genital sores associated with syphilis can make it easier to become infected with HIV, the virus that causes AIDS.

Syphilis is easy to cure in its early stages. But without treatment, it can hurt your body’s organs, leading to severe illness and even death.

Causes of Syphilis

The cause of syphilis is a bacterium called Treponema pallidum. The most common route of transmission is through contact with an infected person’s sore during sexual activity. The bacteria enter your body through minor cuts or abrasions in your skin or mucous membranes. Syphilis is contagious during its primary and secondary stages, and sometimes in the early latent period.

Less commonly, syphilis may spread through direct unprotected close contact with an active lesion (such as during kissing) or through an infected mother to her baby during pregnancy or childbirth (congenital syphilis).

Once cured, syphilis doesn’t recur. However, you can become reinfected if you have contact with someone’s syphilis sore.

Symptoms of Syphilis

Often, syphilis has no symptoms or has such mild symptoms that a person doesn’t notice them.

There are also several stages of syphilis, which may overlap. The stages may be separated by latent stages, or times when no symptoms are present.

Symptoms vary with each stage. But the syphilis symptoms do not always occur in the same order.

Primary Stage

A single sore, called a chancre (SHANG-kuhr), appears in the first, or primary stage. Sometimes, more than one sore appears. The time between infection with syphilis and the start of the chancre can range between 10 to 90 days (21 days average). The chancre is usually firm, round, small, and painless. It appears at the spot where the infection entered the body, such as the vulva, vagina, cervix, tongue, lips, or other parts of the body. In this stage, syphilis can be passed to others through contact with the chancre during vaginal, anal, or oral sex. The chancre lasts 3 to 6 weeks and heals with or without treatment. If the infection is not treated, it moves to the secondary stage.

Secondary Stage

The secondary stage can start as the chancre is healing or a few weeks after it has healed. It typically starts with a rash on 1 or more areas of the body. Some or all of these symptoms can appear:

  • Skin rash with rough, red, or reddish-brown spots both on the palms of the hands and bottoms of the feet. The rash usually does not itch. Rashes on other parts of the body may not look the same.
  • Sores on the throat, mouth, or cervix
  • Fever
  • Swollen glands
  • Sore throat
  • Patchy hair loss
  • Headaches and muscle aches
  • Weight loss
  • Tiredness

In this stage, the infection can be passed to others through contact with open sores or rash during vaginal, anal, or oral sex. Rash and other symptoms will go away with or without treatment. But without treatment, the infection will move to the latent and possibly late stages of disease.

Latent Stage

The latent, or hidden, stage starts when symptoms from the first and second stages go away. The latent stage can last for many, many years. During this stage, the infection lives in the body even though there are no signs or symptoms. The infection cannot be passed to others during the latent stage. Sometimes, symptoms from the secondary phase come back. If this happens, the infection can be passed to others until the symptoms go away again. Without treatment, the infection will advance to the late stage in some people.

Late Stage

About 15 percent of people with untreated syphilis will advance to the late stage. This can happen within a few years or as many as 20 years or more after first becoming infected. In the late stage, the disease can hurt your organs, including the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. This damage can lead to nerve problems, paralysis, blindness, dementia, and other health problems. Some people may die from the disease. You will only reach the late stage if you do not receive treatment earlier. If you have syphilis, get treated as soon as possible to avoid these problems.

Syphilis Diagnosis 

Syphilis can be diagnosed by testing samples of:

  1. Blood. Blood tests can confirm the presence of antibodies that the body produces to fight infection. The antibodies to the bacteria that cause syphilis remain in your body for years, so the test can be used to determine a current or past infection.
  2. Fluid from sores. Your doctor may scrape a small sample of cells from a sore to be analyzed by microscope in a lab. This test can be done only during primary or secondary syphilis, when sores are present. The scraping can reveal the presence of bacteria that cause syphilis.
  3. Cerebral spinal fluid. If it’s suspected that you have nervous system complications of syphilis, your doctor may also suggest collecting a sample of cerebrospinal fluid through a procedure called a lumbar puncture (spinal tap).

Through the Centers for Disease Control and Prevention, your local health department offers partner services, which will help you notify your sexual partners that they may be infected. That way, your partners can be tested and treated and the spread of syphilis can be curtailed.

Treatment for Syphilis

When diagnosed and treated in its early stages, syphilis is easy to cure. The preferred treatment at all stages is penicillin, an antibiotic medication that can kill the organism that causes syphilis. If you’re allergic to penicillin, your doctor will suggest another antibiotic.

A single injection of penicillin can stop the disease from progressing if you’ve been infected for less than a year. If you’ve had syphilis for longer than a year, you may need additional doses.

Penicillin is the only recommended treatment for pregnant women with syphilis. Women who are allergic to penicillin can undergo a desensitization process that may allow them to take penicillin. Even if you’re treated for syphilis during your pregnancy, your newborn child should also receive antibiotic treatment.

The first day you receive treatment you may experience what’s known as the Jarisch-Herxheimer reaction. Signs and symptoms include fever, chills, nausea, achy pain and headache. This reaction usually doesn’t last more than one day.

Treatment Follow-Up

After you’re treated for syphilis, your doctor will ask you to:

  • Have periodic blood tests and exams to make sure you’re responding to the usual dosage of penicillin
  • Avoid sexual contact until the treatment is completed and blood tests indicate the infection has been cured
  • Notify your sex partners so that they can be tested and get treatment if necessary
    Be tested for HIV infection

How Does Syphilis Affect A Pregnant Woman And Her Baby?

Depending on how long a pregnant woman has been infected with syphilis, she has a good chance of having a stillbirth (birth of an infant who has died prior to delivery) or of giving birth to a baby who dies shortly after birth.

If not treated immediately, an infected baby may be born without symptoms but could develop them within a few weeks. These signs and symptoms can be very serious. Untreated babies may become developmentally delayed, have seizures, or die.

Syphilis Prevention

There are steps you can take to lower your risk of getting syphilis:

  • Don’t have sex. The surest way to keep from getting syphilis is to practice abstinence. This means not having vaginal, oral, or anal sex.
  • Be faithful. Having a sexual relationship with one partner who has been tested for syphilis and is not infected is another way to lower your risk of getting infected.
  • Be faithful to each other. This means you only have sex with each other and no one else.
  • Use condoms. Syphilis sores can occur in places that are covered by a condom, as well as areas that are not covered. So, using a condom the right way and every time you have vaginal, anal, or oral sex might lower your risk. For vaginal sex, use a latex male condom or a female polyurethane condom. For anal sex, use a latex male condom. For oral sex use a male latex condom. A dental dam might offer some protection during oral sex (mouth to vagina/anus).
  • Know that some methods of birth control, like birth control pills, shots, implants, or diaphragms, will not protect you from STIs, including syphilis. If you use one of these methods, be sure to also use a latex condom every time you have sex.
  • Talk with your sex partner(s) about STIs and using condoms. It’s up to you to make sure you are protected. Remember, it’s your body!
  • Talk frankly with your doctor and your sex partner(s) about any STIs you or your partner has or has had. Talk about symptoms, such as sores or discharge. Try not to be embarrassed. Your doctor is there to help you with any and all health problems. Also, being open with your partners can help you protect your health and the health of others.
    Have a yearly pelvic exam. Ask your doctor if you should be tested for syphilis or other STIs, and how often you should be retested. Testing for many STIs is simple and often can be done during your checkup. The sooner syphilis is found, the more likely it can be cured quickly and easily.
  • Avoid using drugs or drinking too much alcohol. These activities may lead to risky sexual behavior such as not wearing a condom.

Syphilis Prognosis

Syphilis is a curable disease with prompt diagnosis and treatment. However, if treated too late, there may be permanent damage to the heart and brain even after the infection is destroyed.