Conditions Syphilis

Syphilis (lues) is a globally prevalent sexually transmitted disease. It is caused by the bacterium Treponema pallidum.

If syphilis is not treated, it can progress in three stages, but also heal spontaneously. There are sometimes no symptoms at all between the stages. The symptoms can be very mild and not all people notice when they have been infected with syphilis. Those affected can therefore transmit the pathogens to others unnoticed.

In Germany, syphilis currently occurs predominantly in men who have sex with men. Reasons for this include frequently changing sexual partners. Fewer men are also using condoms since the development of drugs that can prevent and treat HIV infections.

The treponema bacteria can be transmitted the following ways:

• via small wounds in the skin or mucous membranes during sexual contact
• via the womb to the unborn child of an infected pregnant woman (congenital syphilis)
• in rarer cases, through unclean needles used for drug abuse

Transmission through blood transfusions has been virtually eliminated as blood donations are systematically tested for syphilis.

Only about half of patients with syphilis have symptoms. If it remains untreated, it can progress in three stages with various symptoms, but also heal spontaneously.

First stage (Lues I, primary syphilis)

The first symptoms usually appear an average of 3 weeks after the bacterium is transmitted. In some cases, however, symptoms appear as soon as 10 days later or do not appear for 3 months. To begin with, a small lump develops where the bacteria invade the body. This is usually on the penis or labia, but also in the area of the mouth or anus, depending on sexual practice. The nearby lymph nodes swell up and the lump develops into a hard ulcer, also known as a chancre. The ulcers on the genitals are not painful. The first stage heals by itself after 4 to 6 weeks.

Second stage (Lues II, secondary syphilis) 

After about 4 to 10 weeks, the bacteria spread throughout the body. Various symptoms can then appear with varying severity:

• fever
• headaches, joint pain or muscle aches 
• swollen lymph nodes
• patchy hair loss
• a rash, often initially on the palms and soles of the feet
• flat-topped, weeping lumps (condylomata lata), mainly in the genital region, groin or armpits
• additional callus formation on the palms and soles of the feet

Condylomata lata contain a very high number of bacteria and are therefore highly contagious. The second stage can last for several years and the symptoms may flare up repeatedly.

Third stage (Lues III, tertiary syphilis) 

If the early syphilis is not treated and does not heal spontaneously, various symptoms can appear at a later date. Even after several symptom-free years, syphilis can progress to the third stage. It is then known as late syphilis. The symptoms in this phase can vary in their severity:

• grouped, partially elevated skin lesions that can also form skin defects and crusts in the middle (syphilis tuberosa)
• “gummas”: nodules in the skin and internal organs that can open up and release a viscous fluid (syphilis gummosa)
• vascular changes to the aorta, bulging blood vessels (aneurysms) that can rupture

Risk of infection during the various stages

In the first year after infection, the condition is referred to as early syphilis. In the first and second stages of syphilis, patients are contagious to others, especially in the first stage. If syphilis is diagnosed in the first stage, all sexual partners from the last three months should be informed about the possibility of them having contracted syphilis and tested. If syphilis is diagnosed in the second stage, all sexual partners from the last twelve months should be informed. Once the second stage has passed, patients may not experience any symptoms of the illness for several years (latent phase). However, the illness can still be transmitted to others even in the early latent phase. In the subsequent stages (late syphilis), the risk of the illness being passed on is very low.

Neurosyphilis

Syphilis can also affect the brain and spinal cord. It is then known as neurosyphilis. The attack on the nervous system can cause several symptoms, including:

• headache, nausea and vomiting
• hearing or visual impairments
• strokes
• seizures
• mental symptoms such as confusion, changes in character, thought disorders, hallucinations or restricted mobility
• paralysis, pain and numbness in the lower abdomen and legs (tabes dorsalis)

The cause of syphilis is the bacterium Treponema pallidum. It is globally prevalent and only occurs in humans.

Having unprotected sex and frequently changing partners increases the risk of being infected with syphilis.

You can use an online STI risk test to assess your risk of contracting HIV or other sexually transmitted diseases. The test is available on the website of the WIR – Walk In Ruhr, Center for Sexual Health and Medicine (Zentrum für Sexuelle Gesundheit und Medizin).

The number of reported cases of syphilis has increased since 2010, with the only slight fall in numbers during the COVID‑19 pandemic. In 2024, 9,523 people contracted syphilis in Germany. Around the world, around 8 million new cases were recorded in 2022. Men are affected more often than women.

The progression of syphilis is in stages. In principle, syphilis can heal at any stage, but the resulting organ damage cannot be repaired. 

If the infection is detected early, it can be easily treated with antibiotics. If left untreated, however, the disease occasionally causes severe disabilities and can even be fatal.

Syphilis can get into the body during sex via the smallest of wounds, for example on the genital organs, in the mouth or in the anus. Protected sexual intercourse can reduce the risk of infection. Condoms or femidoms can be used for anal or vaginal sex. Femidoms work similarly to condoms and provide equally good protection but are inserted into the vagina. Both condoms and dental dams can be used for protection during oral sex. Dental dams are thin sheets that can be placed between the mouth and the vagina or anus.

In some cases, an antibiotic can be taken preventively as protection against syphilis. However, this only applies to certain groups of people following situations that involve a particularly high risk of infection. Taking this medication should be discussed with a doctor in advance. As the drug is not approved for preventive treatment in Germany, individuals have to cover the cost themselves.

People with a verified syphilis illness should refrain from all sexual contact until the end of their treatment. Even though it can be awkward, they should also inform all sexual partners who may have contracted the disease. This is the only way that these can also obtain advice and, if necessary, treatment.

Further information on how to prevent sexually transmitted diseases can also be found in our article Sexually transmitted infections: how to stay protected.

If syphilis is suspected, doctors can take swabs of the affected sites and examine them under a special microscope or with specific laboratory tests. The bacteria can be detected directly in a lab. A positive pathogen detection should always lead to a treatment.  

Laboratories can detect various antibodies in blood samples. There are antibodies with which it is possible to detect contact with syphilis pathogens and antibodies with which the activity of the disease can be determined. With these antibody tests, doctors can decide whether patients must be treated. They also make it possible to record whether treatment was successful.

If neurosyphilis is suspected, spinal fluid is taken and tested.

There are also rapid tests for syphilis. Results of rapid syphilis tests are not as reliable as lab tests. But they can be used as screening procedures and give an indication of an infection. Further antibody tests must then be carried out for accurate diagnostic confirmation.

Where can I get tested?

Anyone who has had sexual contact with someone with syphilis or who experiences symptoms of syphilis should get tested. Regular tests are also recommended for people who frequently change sexual partners. A syphilis test is a standard screening test for pregnant women.

Antibody tests can be performed in a dermatology, gynecology or urology practice, for example. Some GP practices also offer the test.

It is also possible to visit the local health authority or the checkpoints of the German AIDS organization Deutsche Aidshilfe. These offer both advice and tests for various sexually transmitted diseases. They also sometimes use rapid tests instead of antibody tests. The tests at such places are often free of charge although a small fee is sometimes payable. It is also possible to use anonymous self-tests, which then have to be sent to a laboratory.

You can find advice and test centers near you on the website kompass.hiv provided by the German AIDS organization Deutsche Aidshilfe.

Syphilis is caused by bacteria. The disease can be successfully treated with antibiotics. As a general rule, the antibiotic penicillin is used in all stages of the disease. Depending on its stage, syphilis is treated with one to three injections into the gluteal muscle at weekly intervals. In the case of neurosyphilis, the antibiotics are administered via a blood vessel over two to three weeks. Regular antibody tests can be used to check whether the treatment is successful.

If the bacteria decay too quickly as a result of penicillin therapy, the pathogens’ toxic ingredients may cause severe immune system reactions. Symptoms like shivering, fever and headaches then occur. To alleviate the symptoms, doctors often also prescribe the drug cortisone at the start of the course of treatment with antibiotics.

Once treatment has ended, regular check-ups and blood tests are performed. These are used to determine both the extent to which the symptoms have disappeared and the extent to which the number of certain antibodies in the blood is decreasing. 

With early syphilis, the symptoms usually recede quickly after therapy. Sufferers should avoid sexual contact until full recovery. However, organ damage incurred as a result of late syphilis cannot be reversed and may lead to permanent impairments.

Syphilis is a notifiable disease. The reports are made anonymously by the laboratory that detected the disease.

Where can I get help and advice about sexually transmitted diseases (STIs)?

On the “Liebesleben” (Love life) website of the Federal Institute for Public Health (Bundesinstitut für Öffentliche Gesundheit, BIÖG), you will find information about support and advisory services, including phone and online options. The website also provides information about love, sex and protection.

The Caritas website offers information about support and advisory services in your area as well as anonymous online support.

WIR – Walk in Ruhr, Center for Sexual Health and Medicine (Zentrum für Sexuelle Gesundheit und Medizin) also provides useful information on syphilis and other sexually transmitted infections.

Information about sexually transmitted infections can also be found on the website of the German STI Society (Deutsche STI-Gesellschaft – DSTIG).