What Is a Syphilis Sore (Chancre)?

Syphilis is a sexually transmitted infection. It can cause sores on the body known as chancres. These can appear in the genital area as well as other parts of the body, like the anus.

Learn more about chancres, where they are found, other symptoms that may accompany them, how syphilis is diagnosed, and when to see a healthcare provider.

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Signs of a Syphilis Sore (Chancre)

A chancre is a sore that forms on the body. It is often one of the first indications of a syphilis infection.


In the primary stage of syphilis, a single sore or multiple sores may appear. They will typically (but not always) be round and firm. They may not be noticeable, as they are usually painless. The sore will usually be present for three to six weeks.


Chancres will appear in places where a syphilis infection has entered the body. This can be in or around the:

  • Vagina
  • Penis
  • Rectum
  • Anus
  • Lips
  • Mouth

Additional Symptoms of Syphilis

Chancres aren't the only symptom that may occur with syphilis. Other possible symptoms include:

  • Swollen glands in the armpits, groin, or neck
  • Headache
  • Pain in the joints
  • Fever
  • A blotchy red rash (most commonly on the palms and the soles of the feet)
  • Hair loss that is patchy
  • White patches found in the mouth
  • Skin growths that are similar in appearance to genital warts

When to See a Healthcare Provider

Anyone who has symptoms of syphilis should contact their healthcare provider.

Those who engage in certain behaviors would also benefit from speaking with a medical professional. These include:

  • Those who have had intimate contact with someone who has tested positive for syphilis or other STIs
  • Those who engage in sexual practices considered high risk, like having multiple or unknown sexual partners


The only way to definitively diagnose syphilis is through testing. A healthcare provider may use a variety of tests to reach a diagnosis. These may include:

  • A swab test takes fluid from sores to be tested.
  • A physical exam involves a healthcare provider examining the genital area and other areas for sores and rashes.
  • A blood test can indicate if syphilis is present or if an infection has occurred in the past.

Who Should Be Tested and When

Anyone with symptoms of syphilis should be tested as soon as symptoms appear. They should also be tested if they find out their sexual partner has tested positive for syphilis.

Others who should be tested include:

  • Those who have unprotected sex
  • Those who have had STIs previously
  • Men who have sex with men
  • Those with multiple sexual partners


Syphilis can be treated with antibiotics. However, antibiotics may not treat any lasting damage caused by a syphilis infection.

Antibiotics that may be used include penicillin G benzathine or—for those with allergies to penicillin—doxycycline.

Treatment Is Necessary

Although syphilis symptoms like chancres may resolve within a few weeks without treatment, treatment is still necessary.

If left untreated, syphilis can progress to later stages which can result in serious medical complications. Some of these complications can be life threatening.


Syphilis is a sexually transmitted infection. It can produce sores on the body known as chancres. These may appear on the genitals, rectum, anus, mouth, and lips.

Syphilis can spread by intimate contact with someone who has chancres. However, the infection can also be spread between infected people who don't have sores.

Syphilis can be diagnosed through a variety of tests and treated with antibiotics. Although chancres may go away on their own without treatment, treatment is necessary to prevent syphilis from progressing to more serious stages of infection that can be life threatening.

A Word From Verywell

Sexually transmitted infections can be uncomfortable. But if you are dealing with symptoms that concern you or suspect you may have syphilis, there is help available. Don't hesitate to reach out to your healthcare provider for support.

Frequently Asked Questions

  • Are syphilis chancre sores painful?

    Typically (but not always), chancres are painless. Some people don't even notice them.

  • Can you pop a syphilis chancre?

    No, you should not pop a syphilis chancre. Syphilis chancres may go away on their own, without any treatment. However, antibiotics are the only way to successfully treat the infection and prevent it from progressing to more serious stages.

  • How big is a syphilis sore?

    Typically, a chancre is less than 2 centimeters (3/4 inch) in size.

  • Can you pass syphilis without a sore?

    Syphilis can be transmitted between people even without the presence of a chancre or rash.

    Syphilis can also be spread from an infected mother to an unborn baby.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Centers for Disease Control and Prevention. Syphilis – CDC basic fact sheet.

  3. NHS. Syphilis.

  4. MedlinePlus. Syphilis.

  5. MedlinePlus. Syphilis tests.

  6. Penn Medicine. Syphilis.

  7. O'Byrne P, MacPherson P. SyphilisBMJ 2019; 365 :l4159 doi:10.1136/bmj.l4159