It might surprise you to know that syphilis still infects about 130,000 people in the U.S. every year.
Here's Your Full Debrief On Syphilis Symptoms, Stages, and Treatment
Credit: Alex Sandoval

Syphilis may have made an appearance in your social studies textbooks (its stigmatized history is surprisingly well documented for a sexually transmitted infection), but that doesn't mean it's an issue of the past.

"There's a widespread misconception that syphilis is an infection that used to impact people but doesn't anymore," says HIV expert Emily Rymland, D.N.P., F.N.P.-C., clinical development manager at telehealth platform Nurx. But syphilis is very much an infection that people living in the twenty-first century can contract and transmit.

In fact, nearly 130,000 people test positive for syphilis in the United States every year, according to most recent statistics about the rates of sexually transmitted infections from the Centers for Disease Control and Prevention (CDC). (For context, that's about three times as many new cases as HIV annually.)

"The number of syphilis cases has continued to rise over the last 20 years due to a combination of inadequate testing, the stigma around sex, and lack of education," says Rymland. To help close that very real sexual health education gap, keep reading below for everything you need to know about the STI, including info on syphilis symptoms, syphilis treatment, syphilis testing, and prevention. (Related: The Complete Guide to At-Home STD Tests)

What Is Syphilis?

Put simply, syphilis is a bacterial sexually transmitted infection caused by the Treponema pallidum bacterium. While, yes, syphilis is curable, if left untreated, the infection can stay in the body for decades, with symptoms getting progressively more severe. (That's why it's important to know your current STI status, but more on that below.)

Syphilis can be transmitted during any kind of sex (vaginal, oral, anal, etc.) with a person who has syphilis, she says. It can also be transmitted from a parent with syphilis to a fetus during pregnancy through the placenta. (This is known as congenital syphilis.)

Syphilis Symptoms and Syphilis Stages

The symptoms of syphilis vary depending on which stage of syphilis you're talking about. But — and this is very important to note — it's very possible to be asymptomatic or have such mild symptoms that you don't notice them, which can of the risk for transmission if you're unaware. Syphilis symptoms can also be confused for other health conditions (think: herpes sores or other rashes), so it's important to see your doc to know for sure.

Primary-Stage Syphilis

The telltale sign during this syphilis stage is a chancre, which is the name for a syphilis sore. Firm, round, and often the same color as your skin, chancres can occur in or on the genitals, anus, or mouth, says Rymland. "They're typically painless, so therefore often missed by patients," she says.

Chancres most commonly occur at the initial site of infection within three weeks of exposure. "These sores usually last three to six weeks total and go away on their own," says Rymland. A person is most likely to transmit the infection to someone else when these syphilis sores are present, she says. Typically, these syphilis sores disappear without a trace, occasionally, leaving behind a small scar.

It's worth noting that another symptom you might experience during this phase is swollen lymph nodes.

Secondary-Stage Syphilis

"Because the [syphilis] sores from the primary [syphilis] stage are painless and may be in an area that's difficult to see, many people don't notice them," says Rymland — and therefore don't get tested or treated. In that case, you will likely progress to the secondary syphilis stage. During this stage, you're still highly contagious, according to the University of Michigan Health System.

"If you don't get treated for syphilis when it's in its primary stage and it progresses to the secondary stage, you may experience rashes — especially on the palms and soles of your feet — and lesions in various areas of your body," she says. These syphilis rashes typically consist of tiny red, brown, or tan bumps that can either be flat or raised on the skin and likely won't itch. As for the lesions, they're typically mucous membrane lesions, aka sores in your mouth, vagina, or anus, according to the CDC. (Note: If you're wondering exactly what syphilis sores and rashes looks like, the CDC has some helpful photos.)

During this syphilis stage, you may also have a high fever, headaches, swollen lymph nodes, and experience fatigue, which are all general signs of infection, says Rymland. "Eventually, all of these symptoms will go away, even if untreated, but you'll still be positive," she says. Once that happens, you're in the latency stage.

Latency Stage and Late-Stage Syphilis

The latency syphilis stage is colloquially known as the "hidden stage" because "during the latency stage, you'll have zero symptoms, but will still be positive for the infection," says Rymland. Someone could live in this stage for decades (10-30 years!) without experiencing any symptoms.

Eventually, the infection may develop into late-stage syphilis, which is when the infection begins to run rampant in the body. (This happens in just under one-third of people with syphilis.)

"Late-stage syphilis can lead to serious health problems in the brain, bones, liver, and more, and eventually lead to death," says Rymland. Syphilis can also cause nerve, eye, or ear damage, according to the CDC.

You're generally contagious during the early part of the latent stage and may still be contagious during the latent period, even when no symptoms are present, according to the University of Michigan.

When and How to Get Tested for Syphilis

"If you experience any of these [aforementioned] symptoms and haven't been tested for syphilis lately, get tested," says Rymland.

But, again, not everybody who has syphilis will be symptomatic. So, regardless of whether or not you're experiencing symptoms associated with syphilis, she recommends getting tested for syphilis at least once a year — and more often if you don't know the STI status of your recent and/or current sexual partner(s). (See: Here's How Often You Should Be Getting Tested for STIs)

The good news: Getting tested for syphilis is easy. If you have an open throat, anal, or genital sore, your doctor can take a sample of the fluid. If you don't have any sores, your doctor will collect a small blood sample. "You can get either of these tests at a local clinic or lab," says Rymland. "If you're insured, your insurance should cover it."

Another option is to get an at-home STI test that includes syphilis testing. For example, Nurx offers at-home STI testing kits that test for syphilis (and a number of other pertinent STIs). "These kits come with a lancet, which is a small needle for pricking your finger," explains Rymland. "You squeeze a few drops of blood out, return the sample to the lab in a prepaid envelope, and then get your results within a few days," she explains. This is an especially great option for those who don't have access to transportation or child-care.

Exactly What Syphilis Treatment Entails

Ultimately, your treatment regimen will depend on how long you've been infected, says Rymland. "If you've had syphilis for less than one year — which you'll be able to discern if you've been getting tested annually or depending on your current symptoms — [syphilis] treatment is a one-time injection of BiCillin, which is an injectable antibiotic."

If you've had syphilis for over one year, treatment involves three antibiotic shots, all one week apart. If, however, you're experiencing symptoms associated with late-stage syphilis, you'll be treated daily for 28 days with a penicillin IV (usually in your arm), she says.

If you test positive, be sure to tell your partner(s) so that they can be tested and treated, too. (More Here: What to Do If You Have a Positive STI Diagnosis)

How to Protect Against Syphilis

You can prevent syphilis more or less the same way you'd protect against any other sexually transmitted infections.

That means knowing your own current STI status, communicating your current STI status with all sexual partners and asking for theirs, and practicing safer sex with any lover(s) who is positive for syphilis or any other STI, or who's current STI status you don't know.