What’s the Difference Between Syphilis and Herpes?

December 28, 2023
Avatar for Jyoti KinghornJyoti Kinghorn
Herpes or syphilis

Syphilis and herpes are two common sexually transmitted infections (STIs). Both infections are marked by the formation of sores on the body and a relative lack of symptoms. However, these are distinct infections caused by different pathogens.

Syphilis and herpes are caused by different pathogens


Syphilis is a bacterial infection caused by the bacterium Treponema pallidum. It can be completely cured by antibiotics, usually penicillin.

Herpes on the other hand is a viral infection caused by the Herpes simplex virus (HSV).

While antiviral and other treatments can help calm the symptoms, to date there is no cure for HSV infection. Once you have it, you have it for life.

Difference in prevalence

Herpes is the second most common STI in the U.S. There are two main forms of herpes- oral herpes caused by the HSV-1 virus, and genital herpes caused by the HSV-2 virus. It is estimated that 50-80% of U.S. adults have oral herpes caused by the HSV-1 virus. Nationwide, about 12% of persons aged 14-49 have genital herpes caused by the HSV-2 virus.

Syphilis is less common, but the number of people infected every year is on the rise. In 2021, over 177,000 cases of syphilis were reported, making it the seventh most common STI in the U.S.

Herpes sores on face

Differences in Transmission

Syphilis spreads by coming in contact with a syphilitic sore usually during oral, vaginal sex, or anal sex with someone with an active sore. People can have active sores on the penis or scrotum, in or around the vagina, the anus, or the mouth.

Oral herpes is spread by coming in contact with blisters or open sores (cold sores) around the mouth. The virus is extremely contagious. It can spread by oral sex, kissing, and other forms of skin-to-skin contact with someone who is having a symptom outbreak. Oral sex can transfer the HSV-1 virus to the genitals where it can cause genital herpes.

Oral herpes does not have to be sexually transmitted. Many children contract HSV-1 during their preschool years where they come in contact with other children who have cold sores. 

Genital herpes spreads by having vaginal, oral, or anal sex with someone, particularly when they have open ulcers or blisters that may be oozing or bleeding.

Herpes can be painful

Differences in symptoms and stages


The first symptoms of herpes infection are blisters and ulcers.

Timing. Blisters and ulcers appear 2-12 days after first getting infected with HSV-1 or HSV-2.

Appearance. Herpes blisters and ulcers are usually 1-3 mm in diameter, and can be bunched into “crops”.

Spread on the body. Oral herpes appears on the mouth and lips, but can also appear inside the mouth e.g. gums, tongue, or the roof of the mouth. Genital herpes in females appears on the vagina (usually inside the vagina), vulva, anus, buttocks, anus, or thighs. In males, it appears on the penis or scrotum.

Pain. Very often the blisters are painful and itchy. Even before they appear, people can feel itching, burning, and tingling feeling on the skin where they will form. The blisters eventually open to form ulcers that would crust over and heal over the next two weeks revealing healed skin.

Other symptoms: Oral herpes can cause headaches, swollen lymph nodes, and general flu-like symptoms. Genital herpes can cause blisters on or around the mouth, fever, pain in joints, headache, and difficulty urinating.

Treatment: Some medications can help in managing the condition. If someone feels that they might have an outbreak, taking medication before the outbreak can help reduce the symptoms and the duration of the outbreak.

Future episodes: The first blistering event is usually the worst in the intensity of symptoms and how long it takes to get better. After that, herpes symptoms can come and go throughout a person’s life. Some events can trigger a flare-up. These include exposure to sunlight, extreme emotional stress, fatigue, and illnesses that cause fever. Menstrual periods in females can cause a recurrence of symptoms.

There is presently no cure or vaccination for oral or genital herpes. However, candidates for herpes vaccines are currently in various stages of preclinical and clinical development.


The first symptom of syphilis infection is the development of a syphilitic sore.

Timing. The sore shows up about 21 days after being infected. In some cases, it can take as long as 3 months to appear.

Appearance. The sore is often (but not always) firm and round, usually about 0.3-3 cm in diameter.

Spread on the body. The sore or sores occur in genital areas such as in the vagina or on the penis, in or around the anus, and in or around the mouth.

Pain. Syphilitic sores normally don’t itch or hurt. They heal in 3-6 weeks without treatment and can leave a scar.

Treatment. Syphilis does not get better on its own, it requires treatment. However, antibiotics can completely cure syphilis. The sooner they are taken, the lesser the damage the infection does to the body.

Other symptoms and future conditions. Syphilis that has been treated early is unlikely to have any long-term effects. Unless there is a repeated sexual encounter with someone who has syphilis, the infection will not come back after treatment.

However, untreated syphilis can spread the infection in the body. Untreated syphilis has 4 main stages:

  • A contagious primary stage in which a syphilitic sore appears.
  • A contagious secondary stage in which the whole body can get covered in a rash along with possible fever, headache, fatigue, and loss of hair.
  • A latent stage in which the symptoms are absent for the most part, but the infection is still active and can pass from a pregnant person to their fetus.
  • A tertiary stage in which the disease starts causing organ damage. It can damage the eyes and the heart. It can also damage blood vessels that supply blood to the brain and the spinal cord, causing a variety of neurological symptoms including memory loss and paralysis.

The information provided in our blog posts is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this blog.

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