Syphilis - primary

Alternative names
Primary syphilis

Syphilis is one of the more frequently diagnosed and reported sexually transmitted diseases. A chancre is the typical sore of primary syphilis.

Causes, incidence, and risk factors

Syphilis is an infectious disease caused by the corkscrew-shaped bacterium (spirochete), Treponema pallidum. This organism causes infection when it penetrates broken or abraded skin or mucous membranes, usually of the genitals. Transmission occurs most frequently through sexual contact, although other means of transmission are possible.

Syphilis occurs worldwide. In the United States, about 10,000 cases occur annually. The rate of syphilis is higher in urban, rather than rural, areas, and the disease occurs most frequently in the Southern states. Young adults, ages 15 to 25, are the highest risk population. There is no natural resistance to Syphilis.

Because people may be unaware that they are infected with syphilis, many states require tests for syphilis prior to marriage. All pregnant women who receive prenatal care are screened for syphilis to prevent congenital syphilis, which is syphilis infection transmitted from the mother to the newborn.

Syphilis has three commonly recognized stages: primary syphilis, secondary syphilis, and Tertiary syphilis. From a medical standpoint, the actual stages are primary, secondary, latent (hidden), benign late, and tertiary. Syphilis can also affect the unborn child of an infected mother (congenital syphilis).

Primary syphilis first shows as a small, painless open sore or ulcer (chancre). This ulcer typically appears 2 to 3 weeks after exposure. The often solitary ulcer that appears on the penis is easily visible. However, ulcers that occur on the labia, cervix, anal area, or in the mouth may go unnoticed because they are painless and not easily visible.

The classic-appearing ulcer or chancre is shallow with sharply defined borders and slightly raised edges. The base of the ulcer is clean and free of debris. It is typically painless and is firm to the touch. However, many syphilitic ulcers are not “classic” or typical-appearing, and any ulcer appearing on the genitalia should be evaluated by a doctor.

If left untreated, the chancre typically heals spontaneously within 3 to 6 weeks. It may leave behind a thin, slightly depressed scar. This is the end of the primary stage. The organism continues to multiply in the body, but there is little outward evidence of disease until the appearance of the second stage.

Secondary syphilis, Tertiary syphilis, and congenital syphilis are not seen as frequently in the United States as they were 20 or 30 years ago because of the availability of free, government-run sexually transmitted disease clinics, screening tests for syphilis, public education concerning STDs, and prenatal screening.


  • painless sores       o genital lesions (male)       o genital lesions (female)       o mouth sores       o skin lesions       o sores or lesions on the rectum  
  • enlarged Lymph nodes in the area containing the chancre  
  • a chancre or sore that heals in 4 to 8 weeks

Signs and tests

  • VDRL  
  • FTA-ABS fluorescent treponemal antibody test  
  • dark field examination of fluid from sore  
  • RPR  
  • STS (serologic test for syphilis - any of the other tests may be used)


Syphilis can be treated with antibiotics, such as penicillin G benzathine, doxycycline or tetracycline (for patients who are allergic to penicillin). Duration of treatment depends on the extent of the syphilis and factors such as the overall health of the patient.

Syphilis during pregnancy: Penicillin is recommended as the drug of choice. Tetracycline cannot be used because of toxicity to the fetus, and erythromycin may fail to prevent congenital syphilis in the fetus. Penicillin-allergic individuals should ideally be desensitized, then treated with penicillin.

Several hours following the treatment of early stages of syphilis, individuals may undergo a reaction called Jarish-Herxheimer reaction. Symptoms of this reaction include:

  • fever  
  • chills  
  • headache  
  • nausea  
  • general feeling of being ill (malaise)  
  • joint aches  
  • muscle aches

These symptoms usually disappear within 24 hours.

Follow-up blood tests must be done at 3, 6, 12, and 24 months to ensure the infection has been eliminated. There must be abstinence from sexual contact until two follow-up tests have indicated that the infection has been cured. The sexual partner should also be treated. Syphilis is extremely contagious in the primary and secondary stages.

Expectations (prognosis)

Syphilis can be completely cured if diagnosed early and treated thoroughly.


Calling your health care provider

Call for an appointment with your health care provider if you have symptoms suggestive of syphilis.

If you have had intimate contact with a person who has syphilis or any other STD, or have engaged in any high-risk sexual practices including having multiple or unknown partners, or using intravenous drugs, you should contact your doctor or be screened in an STD clinic.


People with multiple sex partners, unknown partners, or sex partners involved in any high-risk sexual practices are at risk for acquiring sexually transmitted diseases. A person who recognizes that he or she is at risk has taken the first step toward prevention.

Ideally, monogamous sex with a healthy partner remains, short of total abstinence, the safest type of sexual relation. Protected sex (that in which condoms are used) is the next most reliable method of preventing STDs.

Condoms act as a barrier to the transmission of infectious organisms (pathogens), and should be used in any and all situations which would be considered risky or high risk. (See condoms for prevention of sexually transmitted disease.)

Syphilis is a reportable disease, as required by law. The infection must be reported by the health care provider to public health authorities. Information acquired from reporting helps the public health investigators identify, locate, and treat infected sexual contacts. This function helps prevent the continued spread of infection.

Johns Hopkins patient information

Last revised: December 8, 2012
by Armen E. Martirosyan, M.D.

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