Syphilis is typically transmitted via direct contact with a syphilitic sore, also called a chancre. Chancres are usually located on the genitals, vagina, anus, rectum, lips, and mouth.
Syphilis cases have steadily climbed since the lowest reported number of new cases in 2000, with 134,000 new cases reported in 2020.
Without treatment, syphilis can progress through different stages and cause significant health problems. Untreated, the person infected with syphilis remains contagious and can infect other people.
Signs of Syphilis
Syphilis symptoms depend on the stage the infected person is in. Syphilis is associated with four stages:
Primary stage: During the primary stage, the syphilitic sores, or chancres, develop. The sores are often painless and tend to develop on the genitals, mouth, or inside the vagina or anus. The chancres usually heal within three to six weeks. Secondary: Symptoms associated with the secondary stage include a rash, sores in moist areas (such as the mouth, genitals, or anus), fever, fatigue, sore throat, weakness, hair and weight loss, and swollen lymph nodes. Latent: In this stage, all of the symptoms from the secondary stage end, often resulting in the latent stage’s reputation as the “hidden stage. " People infected with syphilis can stay in the latent stage for years. Sometimes, people infected with syphilis might experience the secondary stage two or more times and then go back to the latent stage for a period of time. Tertiary: In the tertiary (or “destructive”) phase of syphilis, the person infected will develop gummas, which are sores that grow deep and eat away at the area where they develop, such as the skin, lungs, liver, or bone. A person infected with syphilis can also develop cardiovascular syphilis, which attacks the heart and blood vessels, or neurosyphilis which attacks the nerves, spinal cord, and brain. Ultimately, without treatment, syphilis becomes so damaging to the body that it can cause death.
Diagnosis
Syphilis is detected by an antibody blood test. A healthcare professional will use a small needle and insert it into a vein in the arm. When inserted, a blood sample is withdrawn and sent to a laboratory for multiple antibody testing. The blood is tested for several antibodies specific to syphilis. Even after successful treatment, a person previously infected with syphilis can still have detectable antibody levels in the blood. This is why several types of antibody testing are completed to determine if it is a prior infection or a new infection.
Treatment
Treatment is based on the age of the person infected with syphilis and the stage of syphilis.
For adolescents and adults in the primary, secondary, or early latent stage of syphilis: One dose of benzathine penicillin G, a type of antibiotic, is administered in the muscle. For adolescents and adults with late latent syphilis or latent syphilis of unknown duration: One dose of benzathine penicillin G is administered in the muscle once a week for three weeks. For adults and adolescents with neurosyphilis, ocular syphilis, or otosyphilis: One dose of aqueous crystalline penicillin G is administered through a vein, either every four hours or continuously, over a 10–14 day period. Options for people allergic to penicillin, people infected with syphilis who are pregnant, and newborns born with congenital syphilis: Treatment options vary and should be considered with careful collaboration with a healthcare professional.
Summary
Syphilis is a bacterial infection that spreads by direct contact and usually transmits through sexual activity. When the syphilis bacterium enters the body, the person infected with syphilis can expect initial symptoms to appear within 10–90 days, most often appearing around day 21.
The primary stage begins with a painless syphilis sore, known as a chancre, at the entry point of the syphilis bacterium and is most often located in the mouth, throat, vagina, or anus. Syphilis will progress through secondary, latent, and tertiary stages if not treated. A person remains contagious and can continue to spread syphilis until treatment is complete, even if they don’t show symptoms.
Syphilis is diagnosed through a blood test and is treated mostly with penicillin, a type of antibiotic. Even in the tertiary stage, treatment can stop disease progression, although it might not repair damage already done.
A Word From Verywell
Receiving a sexually transmitted disease diagnosis can generate anxiety, concern, and fear. It is important to work collaboratively with your healthcare professional to receive proper treatment for yourself and your sexual partners. It is important to understand what syphilis is, how the disease progresses, and the available treatment options, as well as how to protect yourself during sexual activity to avoid reinfection.
Some people infected with syphilis might only have one chancre, while others might have several. Even when the chancre resolves (often within three to six weeks), the person infected with syphilis remains contagious.
The rash usually appears on the palms of the hands and/or the soles of the feet. The rash is usually not itchy and is often rough and red/reddish-brown in coloration.