What Are the 4 Stages of Syphilis?

Syphilis is a sexually transmitted disease (STD) and a curable bacterial infection that develops in stages. The earlier it is diagnosed, the easier it is to treat. The primary way syphilis spreads is through sexual contact with an infected person either via vaginal, anal or oral sex.

"Syphilis is caused by a bacterium called Treponema pallidum. It is most often spread through sexual contact," said Ashley Jennings, M.D., a board-certified OB-GYN and a clinical associate professor at the University of Wisconsin School of Medicine and Public Health. "Patients can present with a painless ulcer. When a partner comes in contact with this painless ulcer, they can be infected. Syphilis can also be passed from mother to baby during pregnancy so we test for this condition in pregnancy."

Incidents of syphilis are rising, especially among men who have sex with men (MSM), although anyone can get infected regardless of sexual orientation. The current rates of syphilis have been described as "unacceptably high."

The four stages of syphilis

This STI has four stages and presents with different symptoms at each stage.

Primary stage syphilis

This is the earliest stage of syphilis and is typically characterized by a single canker appearing at the initial site of infection.

Cankers can be visualized as a sore, ulcer or lesion, and they usually show up on the genitals, anus, mouth or lips. In rare cases, more than one canker may appear. A canker may emerge on any part of the skin that was exposed to Treponema pallidum, the syphilis-causing bacteria.

"On average, it takes three to four weeks between exposure and developing this ulcer," said Dana Dunne, M.D., M.H.S., an associate professor of medicine (infectious diseases) at Yale School of Medicine in New Haven, Connecticut. "This non-painful ulcer is considered the primary stage of syphilis and can be located wherever the primary site of contact was—in the mouth (lip, side of throat, tongue), vagina or labia, penis, anal area, etc. Even without treatment, the ulcer goes away on its own and may even go unnoticed."

Cankers are infectious and contagious. If you make contact with a partner's canker during sex, transmission may occur. Keep in mind that a syphilitic canker is painless and not always visible. If it's on a patient's vagina or anus they may not notice it, and it will expose partners to the bacteria during intercourse.

Sexually active people including men having sex with men, persons who have HIV, or persons taking pre-exposure prophylaxis (PrEP) for HIV prevention have a greater risk for contracting syphilis.

It takes cankers three weeks to form (on average) after transmission has occurred, and then another three to six weeks to heal, regardless of whether treatment is received, according to the Centers for Disease Control and Prevention (CDC). This marks the entrance of the next stage of syphilis, which is much more contagious.

Secondary stage syphilis

If a patient does not notice the canker and fails to visit a doctor, the disease will progress to the secondary stage. Most patients who seek medical intervention do it while syphilis is in this stage, according to experts.

While primary stage syphilis may go unnoticed, secondary stage syphilis is harder to ignore or miss.

"The secondary stage occurs two to eight weeks later when the bacteria starts to replicate again, overwhelms your immune system and spreads throughout the bloodstream to almost all body parts," Dunne said. "Since it spreads everywhere in this stage, the symptoms are many and can be easily confused for a number of other illnesses."

This stage comes with a variety of symptoms that may be mild or severe, according to Dunne. In addition, many patients who don't seek medical care during this stage can be misdiagnosed. The symptoms include the following:

• Skin rashes on different parts of the body (palms, soles, mouth, genitals)
• Swollen lymph nodes
• Fatigue
• Headache
• Inflammation of the liver
• Blurry vision (uveitis) or other visual disturbance
• Sudden hearing loss
• Vertigo
• Facial droop
• Severe headache
• Neck stiffness (like meningitis)
• Strokes

"Your immune system will partially be able to deal with the spirochete and all symptoms can resolve," Dunne said. "It is not known whether we actually get rid of the spirochete at this point or if most people are just able to keep it in check for the rest of their lives."

Many experts refer to syphilis as the "great pretender." This is mainly because secondary syphilis has an array of symptoms that resemble those of many other conditions, and it is important to screen the patient carefully using the latest guidelines before drafting a treatment plan.

Secondary stage syphilis is also the most contagious stage of syphilis. While symptoms may vary from patient to patient, the most common is a rash, which appears in 75 percent to 90 percent of patients.

This rash usually occurs in the torso, hands and feet. It is typically non-itchy and referred to as a maculopapular rash. These come in the form of red bumps on the skin, but they may also be flat. Syphilis may cause condylomata lata, or gray warts along the vaginal or anal regions, as well.

Mucous patches are also a good indicator of secondary stage syphilis and may appear on the mouth, vagina or vulva.

It is important to understand that most patients typically end their journey with syphilis at the secondary stage. While there are still cases in the United States in which syphilis progresses, these are usually the exception rather than the rule.

Latent stage syphilis

Much like primary stage syphilis, secondary stage syphilis symptoms will also resolve on their own, regardless of whether treatment was obtained.

If left untreated and syphilis enters its latent stage, a patient will not exhibit any further symptoms, but they may experience occasional flare-ups of secondary stage syphilis-type symptoms. In this stage, a patient is not usually contagious and is unlikely to pass the infection on to others unless they experience that occasional flare-up.

"The stage of syphilis that occurs after secondary symptoms have resolved is called latent syphilis, which means if you had a blood test for syphilis and it was positive but you had absolutely no symptoms and an examination was normal, you would be considered latent," Dunne said.

It is important for healthcare providers to distinguish between secondary stage syphilis and a latent-stage flare-up. While both stages can be treated with antibiotics such as penicillin, the dosage and treatment guidelines differ. The duration of therapy depends on the specific stage of the syphilis.

Latent stage syphilis can only be diagnosed through screening and serological testing. It can last anywhere between 10 to 20 years and sometimes leads to damage to the heart and nervous systems.

Tertiary syphilis 

If syphilis is not addressed in the secondary or latent stages, there is a 30 percent chance it progresses to tertiary stage syphilis, according to researchers, and this is where irreversible damage typically occurs and sometimes even death.

With the advances in medicine, tertiary stage syphilis is incredibly rare (in developed countries) due to the straightforward nature of syphilis treatment with readily available antibiotics.

Tertiary stage syphilis is also referred to as late stage syphilis and can cause structural damage to multiple organ systems and lead to disability. There are three main ways tertiary syphilis may present itself:

• Neurosyphilis. This type of tertiary syphilis could cause dementia, paralysis, vision loss, convulsions, tremors and psychiatric disease.
• Cardiovascular syphilis. This type could cause heart failure.
• Gummatous syphilis. A 'gumma' is a destructive lesion caused by a severe inflammatory response that typically destroys significant chunks of skin or bone.

"A small percentage (15 percent to 20 percent) of patients, if left untreated, would progress to late syphilis stages called tertiary syphilis," Dunne said. "Patients diagnosed with any of the earlier stages would be treated, so the way researchers know how many patients would develop late tertiary syphilis is based on old descriptive studies."

How to avoid syphilis

It's important to practice safe sex because studies have estimated that nearly 30 percent to 60 percent of people who come into sexual contact with a person in the early stages of syphilis will develop syphilis. While using condoms or dental dams will not guarantee protection, they significantly mitigate the risk of transmission.

If you suspect you've been exposed, it is important to immediately get screened because its symptoms mimic a variety of other diseases.

Treatment of syphilis is straightforward and requires antibiotics, such as penicillin. The dosage and duration of treatment depend on the stage of syphilis, and the earlier it is diagnosed, the easier it is to cure.

"Because syphilis rates have been rising in recent years, it's important to get screened if you have a partner who has had syphilis or if you are at higher risk for contracting it," said Amanda Thornton, M.D., an infectious disease physician for Kaiser Permanente in Northern California. "Sexually active people including men having sex with men, persons who have HIV, or persons taking pre-exposure prophylaxis (PrEP) for HIV prevention have a greater risk for contracting syphilis because syphilis can be confused with so many diseases and symptoms can be mild, apparently resolving without treatment, it can be easily missed. That's why screening is so important, even if a person doesn't have symptoms.

"A pregnant person with syphilis can pass on the disease to the fetus," she said. "Infecting an unborn baby can lead to a low birth weight, premature delivery or a baby who is stillborn. Pregnant women should receive syphilis testing at least once and receive immediate treatment if the test is positive. A newborn with syphilis can also develop serious health problems within weeks, so babies born to women with syphilis in pregnancy may need additional treatment."