If “syphilis” sounds like a disease that will hit people in the next century, you’re not alone. For decades, infection was widely considered a disease of the past. But after years of decline, syphilis is quietly making a comeback, with rates now higher than at any time since the 1950s.
And here’s the hard part: no one knows they have it. Because of this, its symptoms can resemble many unrelated conditions, and the disease “develops in stages,” says Dr. Arkideh Alexander says.
Here’s what syphilis is, how to recognize it, how it spreads, and why timely treatment can cure it completely.
What is Syphilis? What does syphilis look like?
Syphilis is a sexually transmitted infection caused by the corkscrew-shaped bacterium Treponema pallidum, says Dr. Crystal Green, a primary care physician at Inspira Health in New Jersey. Although it is less common than sexually transmitted infections such as chlamydia or gonorrhea, it is alarmingly prevalent. Statistics from the World Health Organization estimate that 8 million people aged 15 to 49 worldwide have syphilis in 2022.
Symptoms depend on the stage of the disease. Primary syphilis is the first stage, and usually begins with a single sore called a chancre. It “can be either a painless or a painful nodule that then becomes an open sore or ulcer,” Green explains. While usually found on the genitals, cancer can also appear in the throat or anus. Because the rash heals within three to six weeks—even without treatment—many people ignore it.
If left untreated, the infection progresses to secondary syphilis after about four to 10 weeks. This stage can include fever, chills, swollen lymph nodes, malaise, headache, muscle aches and sometimes “hair loss, stomach pain or joint swelling,” says Dr. Michael Shane says. But he says the hallmark symptom is “a distinctive rash” consisting of faint, non-itchy red-brown spots, often on the palms of the hands and soles of the feet.
After this, the infection may enter a latent phase, during which it causes no symptoms but remains active in the body for years. Without treatment, some people eventually develop tertiary syphilis, which Alexander says can damage the heart, brain and nervous system. “Third syphilis can develop anywhere from one to 30 years after the primary infection,” Green adds.
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How is syphilis?
Syphilis is mainly spread through vaginal, anal or oral sex, Shane explains. Condoms greatly reduce the risk, but they do not eliminate it completely because bacteria can still enter through small breaks in the skin or mucous membranes that are outside the area covered by the condom.
In fact, Green says that because these sores are so contagious — even if they’re small, painless, or hidden — the disease can also be spread through nonsexual contact, including “touching someone with an open, active sore on their body.”
The disease “can also be transmitted from the mother to the fetus in utero,” she adds.
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How is syphilis treated? Can syphilis be cured?
The good news is that “syphilis is a completely treatable sexually transmitted infection at any stage it’s diagnosed,” Green explains. “However, damage to the nervous system, heart and other organs in late-stage syphilis can be irreversible.”
The standard treatment is a single injection of long-acting benzathine penicillin G, but “for later stages, you may need to get multiple injections over several weeks,” Shane notes. People with penicillin allergies also have the option of being treated with alternative measures such as doxycycline.
After treatment, follow-up blood tests confirm that the infection is gone. Your doctor may also screen for other STIs and recommend prevention strategies such as consistent condom use, open communication about sexual health and regular STI testing. They may also refer to “doxy PEP” — taking doxycycline within 72 hours of having sex to try and prevent syphilis and other STIs — which the Centers for Disease Control and Prevention recommends to medical providers for gay and bisexual men and transgender women who have had chlamydia, syphilis or syphilis in the past year.
Doctors also help their patients understand the importance of time. “The earlier syphilis is treated, the easier it is to cure and the less long-term harm it causes,” says Alexander.
This article originally appeared in USA TODAY: What is Syphilis? What does syphilis look like?
