Syphilis and treatment, what is

Syphilis is a sexually transmitted infection. It iscaused by a bacteria.

What is syphilis?

Syphilis is a sexually transmitted infection. It is caused by a bacteria called Treponema pallidum.

How do you get syphilis?

You can get syphilis when you have sex with someone who is already infected. You can get infected by vaginal sex, oral sex or anal sex, and even from deep sensual kissing. Pregnant women can pass syphilis to their unborn babies.

The infection is more common in men, who have sex with men, people who frequently change sexual partners and who do not use condoms during sex.

Travelling to different parts of the world like Eastern Europe, South-east Asia, Africa and South America, carries an even higher risk of getting syphilis through unprotected sex. Even though you have had syphilis before, you can still get it again.

What are the symptoms?

The signs and symptoms are the same in both men and women. There are 4 stages of the infection.


In the primary stage of syphilis an ulcer (chancre) develops where the bacteria enter the body, usually about 2 – 3 weeks after having sex with an infected person, but it may appear anytime up to three months later.

There is usually one ulcer which is painless, and this is most commonly on the penis, or on the vulva. It can also occur in the vagina, or in the anal canal or in the mouth where it rarely causes any symptoms and then can be unnoticed. Occasionally there may be several ulcers, they may be painful.

The ulcer may take up to 6 weeks to heal and is very infectious to sexual partners.

Skin rash

Secondary syphilis usually appears 3-6 weeks after the appearance of the ulcer if untreated. This stage is caused by the bacteria spreading in your blood stream. You may notice a skin rash, often including the palms of the hands and soles of the feet, lumps in the genital area, swollen glands, or less commonly, patchy hair loss, visual and hearing disturbances or headache.

Secondary syphilis is very infectious to sexual partners.

Without treatment, the rash and other symptoms from secondary syphilis usually disappear after several weeks. However, the symptoms may ‘come and go’ for up to two years.

No symptoms

Occasionally the syphilis symptoms pass unnoticed.

It may take as long as 12 weeks before antibodies against the syphilis bacteria is detectable on a blood test

After the symptoms of secondary syphilis have cleared, you may not have any symptoms for several years, but the infection can be detected on a blood test.

Untreated syphilis

About 3 in 10 people with untreated syphilis will develop serious damaging to the nervous system, brain, bones, or heart. This may be many years later (Tertiary stage).

What is the treatment?

Syphilis is treated with antibiotics, usually penicillin injections. The most common treatment for syphilis is injections with Benzathine penicillin G
(a long-lasting type of penicillin).

Early syphilis treatment consists of one treatment with 2 injections – one in each hip (buttock). You must stay at clinic for 20 min. after the injection to be observed for an allergic reaction. If you have had the syphilis infection for a longer period, or if it is unclear how long you have had it, you will need 3 treatments, given a week a part.

To ensure that the treatment is effective, you will need to have all the injections: If you miss one injection, you will have to start all over.

Reaction to the treatment

4-6 hours after the first injection is given you may experience chills and a high fever, up to 39 – 40 degrees Celsius. The reaction usually last for approximately 8 hours. The reaction is probably caused by the decay of treponema pallidum. The symptoms may be relieved by fx. 1 gram of paracetamol – up to 4 times a day. The day after the treatment you might be sore where the injections were given.

Possible side-effects from treatment

In some cases, patients experience abdominal discomfort and diarrhea. In rare cases, treatment can cause allergic reactions such as rash and urticaria.

Possible complications of syphilis?

Syphilis is unlikely to lead to any long-term complications if the infection is treated quickly. However, in 3 in 10 cases, where syphilis has been left untreated, the bacteria’s can spread through the bloodstream to cause serious infecinfection in other parts of your body, such as your bones, heart and brain. This may take several years to develop.

Once you have been treated for syphilis, some of the antibodies in the blood tests will always be positive. This does not mean you need further treatment, but you need to remember that you have been treated for syphilis (and keep a copy of your blood results) so you can tell doctors in the future if they ask you.

Do I need to tell my partner?

If you have primary syphilis, it is important that your current sexual partner, and any other sexual partner you have had over the last three months, is tested and treated. If you have secondary syphilis it is important to contact partners over the last 2 years.

This is to prevent you getting reinfected, and to prevent your partners from developing complications.

Syphilis and pregnancy

If you are pregnant, syphilis can be passed from you to your baby during the pregnancy. This can lead to miscarriage, still birth or serious illness in the baby (congenital syphilis) if the mother is not treated during pregnancy. If you are found to have syphilis, treatment can be given safely during pregnancy. In Denmark pregnant women are screened for syphilis at the first pregnancy
consultations at their general practitioners.

Opening hours

See the opening hours of the clinic at

Where is the clinic located?

The clinic is located at Bispebjerg Hospital on Nielsine Nielsens Vej 3, Indgang 5, 1st floor. At the hospital’s website there is an interactive map of the hospital.