What is syphilis?

Syphilis is a sexually transmitted disease (STD) caused by the bacterium Treponema pallidum. primary and secondary (P&S) syphilis is the earliest and most transmissible stages of syphilis.  Syphilis can cause serious health problems if not adequately treated. The nation is facing an increase in syphilis rates among both men and women in every region of the country, especially in gay and bisexual men.


How common is syphilis?

In 2018, there were 115,045 new diagnoses of syphilis compared to about 38,739 of HIV infection and 583,405 of gonorrhea. Of the syphilis cases, 35,063 were P&S syphilis. The majority of the cases occurred among gay, bisexual, and other men who have sex with men (MSM).  MSM accounted for 77.6% of all P&S syphilis cases among males in which sex of sex partner was known and 64.3% of P&S syphilis cases among men or women with information about sex of sex partner. However, in recent years, the rate of P&S syphilis has been increasing among MSM as well as heterosexual men and women.

Syphilis and HIV

In the United States, approximately half of men who have sex with men (MSM) with syphilis were also living with HIV. MSM who are HIV-negative and diagnosed with P&S syphilis are more likely to be infected with HIV in the future. Genital sores caused by syphilis also make it easier to transmit and acquire HIV infection sexually.



Correct and consistent use of latex condoms can reduce the risk of syphilis when the infected area or site of potential exposure is protected. However, a syphilis sore outside of the area covered by a latex condom can still allow transmission.

Because chancres can be hidden in the vagina, rectum, or mouth, it may not be obvious that a sex partner has syphilis. Unless a person knows that their sex partners have been tested and treated, they may be at risk of being infected or re-infected by an untreated partner


The best way to avoid transmission of sexually transmitted diseases, including syphilis, is to abstain from sexual contact or to be in a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected.

Partner-based interventions include partner notification, is a critical component in preventing the spread of syphilis. Sexual partners of infected patients should be considered at risk and provided treatment immediately


The definitive method for diagnosing syphilis is visualizing the Treponema pallidum bacterium via darkfield microscopy. Home self-tests kits are also available but not often reliable. These tests are simple, inexpensive, and are often used for screening.


Who should be tested for syphilis?

Any person with signs or symptoms suggestive of syphilis should be tested for syphilis. Also, anyone with an oral, anal, or vaginal sex partner who has been recently diagnosed with syphilis should be tested for syphilis.

Routine testing is recommended for those who

  • are pregnant;
  • are sexually active men who have sex with men (MSM);
  • are living with HIV and are sexually active;
  • are taking PrEP for HIV prevention.



Transmission of syphilis can occur during vaginal, anal, or oral sex, by direct contact with a syphilitic sore, known as a chancre. These chancres can appear on or around the external genitals, in the vagina, around the anus, the rectum, or in or around the mouth. Pregnant women with syphilis can transmit the infection to their unborn child.

Signs and Symptoms

Syphilis is known as “The Great Pretender”, as its symptoms mimics many other diseases. Syphilis typically follows stages that can last for weeks, months, or even years Symptoms appearance can range from 10 to 90 days, but the average time between acquisition of syphilis and the first symptom is about 21 days.


Primary Stage

The appearance of a single chancre marks the primary (first) stage of syphilis symptoms, but there may be multiple sores. The chancre is usually firm, round, and painless. It appears at the location where syphilis entered the body. These painless chancres can occur in locations that make them difficult to notice (e.g., the vagina or anus). The chancre lasts 3 to 6 weeks and heals regardless of whether a person is treated or not. However, if the infected person does not receive adequate treatment, the infection progresses to the secondary stage.

Secondary Stage

Symptoms of secondary syphilis may include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, fatigue and rash. The skin rashes and/or sores in the mouth, vagina, or anus mark the second stage of symptoms. This stage typically starts with the development of a rash on one or more areas of the body. Rashes can appear when the primary chancre is healing or several weeks after the chancre has healed. The rash usually does not cause itching. The syphilis rash may appear as rough, red, or reddish brown spots both on the palms of the hands and the bottoms of the feet. However, rashes with a different appearance may also occur on other parts of the body, sometimes resembling rashes caused by other diseases. The rashes may also be so faint that they are not noticed. Large, raised, gray or white lesions, known as condyloma lata, may develop in warm, moist areas such as the mouth, underarm or groin region. The symptoms of secondary syphilis will go away with or without treatment. However, without treatment, the infection will progress to the latent and possibly tertiary stage of disease.

Latent Stage (Early latent syphilis and Late latent syphilis)

The latent (hidden) stage of syphilis is a period of time when there are no visible signs or symptoms of syphilis. Without treatment, the infected person will continue to have syphilis in their body even though there are no signs or symptoms. Early latent syphilis is latent syphilis where infection occurred within the past 12 months. Late latent syphilis is latent syphilis where infection occurred more than 12 months ago. Latent syphilis can last for years.

Tertiary Syphilis

Tertiary syphilis is rare and develops in untreated syphilis infections;, it can appear 10–30 years after infection was first acquired, and it can be fatal. Tertiary syphilis can affect multiple organ systems, including the brain, nerves, eyes, heart, blood vessels, liver, bones, and joints. Symptoms of tertiary syphilis vary depending on the organ system affected.

Neurosyphilis and Ocular Syphilis

Syphilis can invade the nervous system at any stage of infection, and causes a wide range of symptoms, including headache, altered behavior, difficulty coordinating muscle movements, paralysis, sensory deficits, and dementia.3 This invasion of the nervous system is called neurosyphilis. Ocular syphilis can also occur at any stage of infection. Ocular syphilis can involve almost any eye structure, but posterior uveitis and panuveitis are the most common. Symptoms include vision changes, decreased visual acuity, and permanent blindness.



Selection of the appropriate treatment is important to properly treat and cure syphilis.The recommended treatment for adults and adolescents with primary, secondary, or early latent syphilis is Benzathine penicillin G 2.4 million units administered intramuscularly in a single dose. The recommended treatment for late latent syphilis or latent syphilis of unknown duration is Benzathine penicillin G 7.2 million units total, administered as 3 doses of 2.4 million units administered intramuscularly each at weekly intervals. The recommended treatment for neurosyphilis and ocular syphilis is Acqueous crystalline penicillin G 18-24 million units per day, administered as 3-4 million units intravenously every 4 hours or continuous infusion, for 10-14 days. Treatment will prevent disease progression, but it might not repair damage already done.

Other options for non-pregnant patients who are allergic to penicillin or unable to to obtain the injections include doxycycline. This therapy should be used only in conjunction with close clinical and laboratory follow-up to ensure appropriate serological response and cure. Follow up testing is recommended in 6 and 12 months after initial treatment.  

Will syphilis recur after treatment?

After appropriate treatment, syphilis does not recur. However, having syphilis once does not protect a person from becoming infected again. Even following successful treatment, one can be re-infected. Patients with signs or symptoms that persist or recur or who have a sustained fourfold increase in nontreponemal test titer probably failed treatment or were re-infected. These patients should be retreated.

Persons who receive syphilis treatment must abstain from sexual contact with new partners until the syphilis sores are completely healed. Persons with syphilis must notify their sex partners so that they also can be tested and receive treatment.



What Can You Do If You’ve Received a Syphilis Diagnosis?

After uploading your positive test results to DoctorAlexa, an online doctor will work with you to develop a treatment plan.

If you have been diagnosed with syphilis, you will be required to upload a positive syphilis report. However, if you don’t have a positive syphilis report but you have been exposed to someone with syphilis, you will have to consent to the provider ordering a syphilis lab test at no additional cost