What Is Syphilis?

Syphilis is a sexually transmitted infection (STI) caused by the bacteria Treponema pallidum. You can get the infection through skin-to-skin contact during vaginal, anal, or oral sex. Symptoms of syphilis develop in stages: primary, secondary, latent, and tertiary—and symptoms can worsen in each stage.

To receive a syphilis diagnosis, your provider will usually order two blood tests. The first test looks for antibodies—or, proteins that your immune system makes to fight infections, like syphilis. If the first test is positive, your healthcare provider will order a second test to confirm the results.

The good news: syphilis is curable and you can treat symptoms with penicillin, a type of antibiotic medication. If you cannot take penicillin, your healthcare provider may prescribe another antibiotic to you. How long treatment lasts depends on the stage of syphilis you are in. Starting treatment as soon as you notice symptoms or know you have been exposed to the infection can improve your condition and reduce your risk of other health complications.

Symptoms

Syphilis is sometimes referred to as ''The Great Pretender'' because its symptoms can look like other diseases or STIs. That's why knowing the symptoms of the infection is so important. Keep in mind: syphilis symptoms worsen at each stage and can affect different organs. If you notice symptoms, it's good practice to contact your healthcare provider for testing.

Each stage of syphilis can show different symptoms. Depending on the stage of syphilis you are in, you may experience:

Generally, primary symptoms first appear 10 to 90 days after exposure. If left untreated, secondary stage symptoms can occur two to eight weeks after primary stage sores heal. Keep in mind: symptoms in the primary and secondary stages can heal on their own, even if you don't receive treatment.

Without treatment, you can enter the latent stage of syphilis. Symptoms during this stage tend to be inactive, so you may not experience symptoms at all for several months or years. However, a blood test can still detect if you have the infection.

Thanks to more screening and awareness about STIs, most people don't experience tertiary stage symptoms, as treatment typically begins sooner than this stage. However, if you are in the tertiary stage, symptoms can damage your organs and be fatal.

Causes

Syphilis is an STI caused by the bacteria, Treponema pallidum. You can get the infection during skin-to-skin contact during sex because the bacteria from a rash or sore can break into your skin and mucous membranes.

In most cases, syphilis is transmissible through sex. However, syphilis can also be passed from the birth parent to the fetus during pregnancy. If a birth parent has not been treated for syphilis, their baby can also get syphilis by coming into contact with infectious syphilis rashes or sores during delivery. This is known as congenital (meaning "present at birth") syphilis.

Syphilis is very rarely transmitted through blood transfusions or needle sharing. It’s important to note that you cannot get syphilis through casual contact with objects such as:

• Toilet seats
• Doorknobs
• Swimming pools, hot tubs, or bathtubs
• Eating utensils

Diagnosis

If you have symptoms of syphilis or think you may have been exposed to the infection, it's good practice to visit your healthcare provider for testing. Your provider can order a syphilis test, which looks for antibodies in the blood. Antibodies are proteins made by the immune system when a virus, bacteria, or other harmful substances enter the body to help your body fight the infection.

Syphilis screening and testing often involve two types of antibody blood tests—nontreponemal and treponemal. It's important to note that these blood tests cannot be used to determine the stage, progression, or severity of your infection.

The first test is a nontreponemal test which checks for antibodies that are linked to having a syphilis infection. Nontreponemal tests for syphilis include:

• A blood test called rapid plasma reagin (RPR)
• Venereal disease research laboratory (VDRL) test, which takes a sample of your blood and spinal fluid

However, the antibodies detected by a nontreponemal test are not specific to syphilis infection. The immune system can make these antibodies as a general response to inflammation caused by autoimmune diseases or other infections.

As a result, your provider will order a second confirmatory test if you test positive on the first test. The second test—known as a treponemal test—detects antibodies that your immune system produces that are specific to syphilis. If these antibodies are present, that means you currently have syphilis or were treated for syphilis in the past. Tests that check for syphilis antibodies include:

• Treponema pallidum particle agglutination assay (TP-PA)
• Fluorescent treponemal antibody absorption (FTA-ABS) test
• T. pallidum enzyme immunoassay (TP-EIA)

In some cases, a healthcare provider may take a swab of a syphilis-related rash or sore to conduct a polymerase chain reaction (PCR) test. This test aims to detect the bacteria T. palladium. Keep in mind: PCR tests are only available for people who have active syphilis symptoms.

Treatments

When caught early, syphilis is treatable and curable. The goal of treatment is to prevent or delay syphilis-related health complications and reduce symptoms. However, treatment cannot undo or reverse the damage that syphilis has already caused.

An intramuscular injection (or, shot) of penicillin treats syphilis infection. How long treatment lasts and how much penicillin you take depends on your symptoms and the stage of syphilis you're in:

• Primary, secondary, and early latent syphilis: A single, intramuscular shot of penicillin
• Late latent and tertiary syphilis: A weekly intramuscular shot of penicillin for three weeks

If you are unable to take penicillin or are allergic to the medication, other antibiotic treatments are available. These medications include:

• Monodox (doxycycline)
• Rocephin (ceftriaxone)
• Sumycin (tetracycline)

Your healthcare provider will monitor you for six, 12, and 24 months after treatment to see if the treatment was successful.

Comorbid Conditions

When left untreated during the earlier stages, syphilis infection can cause health complications years later. Tertiary syphilis can cause heart problems, severe skin rashes, and painful lesions on your bones. At any stage, syphilis can spread to the:

• Brain and nervous system (neurosyphilis)
• Eyes (ocular syphilis)
• Ears (otosyphilis) 

Syphilis can also increase a person's risk of acquiring HIV. Open sores caused by syphilis make it easier for the virus to enter the body through sexual activity. People who have syphilis are two to five times more likely to acquire HIV through sex.

How to Prevent Syphilis

The most reliable way to prevent syphilis is to not have vaginal, anal, or oral sex. However, this is not always possible. Therefore, other methods of reducing your risk of the infection include:

• Using condoms or dental dams during sex
• Getting tested for syphilis and STIs with your partners regularly
• Limiting the number of your sexual partners
• Getting screened for syphilis during pregnancy

Find a healthcare provider that you trust and have an open dialogue about your sexual behaviors and risks. Your healthcare provider can help you determine how often you should screen for syphilis and other STIs.

Living With Syphilis 

How fast you recover from syphilis depends on the stage you are in and how the infection affects your body. Primary and secondary stage syphilis can be cured completely if you receive a diagnosis early.

Without treatment, up to 33% of people will have health complications due to syphilis. Tertiary or late stage syphilis can cause permanent disability and may lead to death.

While you are living with syphilis and receiving care, take your treatment as prescribed—even if symptoms go away. It's also important to avoid any sexual activity while you are getting treatment. Do not have sex until syphilis sores and rashes have healed completely.

Having syphilis once does not prevent you from getting it in the future. You can get repeated syphilis infections, especially if your sexual partners have not received syphilis treatment. If you're worried about repeated infections or want to know more about what you can do to protect yourself from STIs, have an open dialogue with your healthcare provider and your sexual partners about what you can do to keep yourself safe.