• Medical Author: Scott E Rudkin, MD, MBA, RDMS
  • Coauthor: Barbara J Blasko, MD
  • Medical Editor: Scott H Plantz, MD, FAAEM
  • Medical Editor: Francisco Talavera, PharmD, PhD
  • Medical Editor: James Ungar, MD

Facts on Syphilis

Pictured is the syphilis bacterium, a spirochete-type organism. Syphilis is a sexually transmitted infection.
Pictured is the syphilis bacterium, a spirochete-type organism. Syphilis is a sexually transmitted infection.

Syphilis (pronounced SIF-uh-lus) is a sexually transmitted disease caused by bacteria. The highly infectious disease may also be passed, but much less often, through blood transfusions or from mother to fetus in the womb. Without treatment, syphilis can cause irreversible damage to the brain, nerves, and body tissues.

The symptoms of syphilis can mimic many diseases. Sir William Osler stated, "The physician who knows syphilis knows medicine."

What Causes Syphilis?

Syphilis is an infectious disease, usually sexually transmitted, disease caused by the bacteria Treponema pallidum. The bacteria penetrate chafed skin or the mucous membranes.

  • Transmission most often occurs when one person comes into contact with lesions on an infected person through sexual activity.
  • Men are more vulnerable to contracting syphilis than women.
  • The active disease is found most often among men and women aged 15-39 years.

What Are the Symptoms or Signs of Syphilis?

Syphilis may progress through 3 distinct stages. Sometimes not all 3 may be evident.

  • Primary phase: The primary phase usually starts with a sore at the site of infection. The sore or lesion is called a chancre (pronounced shanker). This sore usually appears as a painless craterlike lesion on the male or female genitals, although any part of the body is at risk. Anyone who touches an infected sore can become infected. This initial lesion develops 2-3 weeks after infection and heals spontaneously after 3-6 weeks. Though the sore goes away, the disease does not. It progresses into the secondary phase.
  • Secondary phase: The secondary phase may develop 4-10 weeks after the chancre. This phase has many symptoms, which is why syphilis is called "the great pretender." It may look like a number of other illnesses. This phase of syphilis can go away without treatment, but the disease then enters the third phase. These are the most frequently reported symptoms of the secondary phase:
  • Latent (dormant) phase: The early latent phase (first 12 months following infection) is characterized by an absence of symptoms. Patients in this stage are still infectious, however. Late latent syphilis is an asymptomatic stage when the infection occurred more than 12 months earlier, and these patients are generally not infectious. However, you can still transmit the infection from mother to fetus or through blood transfusions.
  • Tertiary Phase: About a third of people with latent syphilis will progress after many years (or decades) into tertiary syphilis. During this phase, the heart, brain, skin, and bones are at risk. Luckily, with the advent of penicillin, this phase is very rarely seen today.
    • Congenital syphilis occurs after a fetus is infected in the womb. This form of syphilis causes teeth abnormalities, bone problems, liver/spleen/kidney enlargement, brain infection, failure to thrive/poor growth, swollen lymph nodes, yellow skin (jaundice), low blood counts, and skin rashes.

When to See a Doctor for Syphilis

  • Contact your doctor to examine any strange sores on your penis or vagina. You should also speak to your doctor about any abnormal rashes that fail to go away within 1-2 days.
  • You should also call your doctor if you develop a new rash, sore throat, joint swelling, fever, or any new symptoms during or after the time you are being treated for syphilis.
  • Although syphilis may be treated in your doctor's office, you should seek emergency care if you have any vision changes, pain with viewing bright lights, a stiff neck, high fevers, or sudden weakness in any part of the body. Syphilis can cause strokes.

What Exams and Tests Diagnose Syphilis?

Syphilis can masquerade as any disease. Therefore, your doctor will carefully sort out the symptoms, ask when they appeared, and take a complete sexual history. The doctor may ask about your use of condoms and if your sexual partners show any similar symptoms.

  • During the primary phase, the doctor will look for a single, painless sore on the male or female genitalia. The mouth, anus, and other parts of the body may also be the site of the initial infection. Lymph nodes near a sore may be swollen.
  • During the primary phase, the doctor may obtain a sample of your sore and perform a dark-field (microscope) exam. This test may also be useful during the secondary phase.
  • Secondary syphilis frequently presents with a diffuse rash and swollen lymph nodes. Your doctor will also ask you about the progression of the rash. Your accurate and descriptive answers are very important. Lesions on the palms and soles of the feet make a diagnosis of syphilis more likely.
    • Blood testing is the cornerstone of diagnosis during the secondary phase. The doctor will usually order one of the following tests. All three help diagnose a syphilis infection.
      • RPR (rapid plasma reagin)
      • VDRL (venereal disease research laboratory)
      • FTA-ABS (fluorescent treponemal antibody absorption) or MHA-TP (microhemagglutination assay for T pallidum)
      • During the tertiary phase, the doctor may need to obtain a sample of your spinal fluid to check for infection and to measure the success of treatment.

Are There Home Remedies for Syphilis?

Only antibiotic therapy will treat this infection. You must seek medical care for this disease.

What Is the Treatment for Syphilis?

Unlike the diagnosis, treatment is fairly straightforward. During the primary, secondary, and early latent phases of syphilis, a single injection of penicillin cures the disease. People who are allergic to penicillin (and not pregnant) may be given oral antibiotics (such as doxycycline, tetracycline, or erythromycin) for 2 weeks.

  • People who are diagnosed to be in the late latent stage of syphilis (and are not sure how long they have been in this stage) and those with tertiary syphilis will require 3 injections, each 1 week apart. Oral antibiotics (most likely, doxycycline or tetracycline) are usually given to people in this stage who are allergic to penicillin.
  • If syphilis has advanced to neurosyphilis (or brain involvement), treatment with IV penicillin every 4 hours for 10-14 days may be required. An alternative is penicillin injections (once per day) with oral probenecid (4 times a day) for 10-14 days.
  • A pregnant woman with syphilis must have penicillin, even if she is allergic to it. She must tell her doctor of this allergy to allow for desensitization procedures.
  • After treatment with penicillin, a Jarisch-Herxheimer reaction may occur 2-12 hours after treatment starts. This reaction is the result of the dying bacteria and may cause previous symptoms to transiently worsen. Alarming as it may be, this reaction usually ends within 24 hours. Bed rest, pain relievers (such as aspirin, acetaminophen, or ibuprofen), and liquids can help.

What Is the Follow-up for Syphilis?

Your doctor will advise you not to have sexual activity until your doctor confirms by blood tests that you are no longer infectious. This may take 2-3 months. It is important for you to advise your sexual partners and close contacts to be checked for syphilis. Your local health department can help.

  • People being treated for syphilis need repeat blood tests at 3, 6, and 12 months to confirm that the disease has been eliminated.
  • People with neurosyphilis need repeat blood tests and spinal fluid examinations every 6 months for at least 3 years.
  • Pregnant women with syphilis need monthly blood testing for the duration of their pregnancy.

How to Prevent Syphilis

Like many other sexually transmitted diseases, syphilis can be prevented with safe sex practices including the use of a condom.

What Is the Prognosis for Syphilis?

  • Syphilis in the first 2 stages continues to be cured with penicillin-unlike other diseases that are becoming resistant to antibiotics.
  • The outlook for people with tertiary syphilis is less optimistic.
  • In one study, 20% of people with cardiovascular syphilis died without antibiotic therapy.
  • However, more than 60% of these people, however, remain symptom free even without treatment.

Health Solutions From Our Sponsors

Man and woman in bed

Syphilis Symptoms in Women

What are the Symptoms?

There are three stages of syphilis, along with an inactive (latent) stage. Formation of an ulcer (chancre) is the first stage. The chancre develops any time from 10 to 90 days after infection, with an average time of 21 days following infection until the first symptoms develop. Syphilis is highly contagious when the ulcer is present.

"Pathogenesis, clinical manifestations, and treatment of early syphilis"