Medical Conditions - Syphilis

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The Facts

Syphilis is primarily a sexually transmitted infection (STI) caused by Treponema pallidum bacteria. The disease has many clinical appearances that are often grouped into stages, depending on when they occur.

There are 3 stages of syphilis during which symptoms appear; however, not everyone will go through all 3 stages. Between these stages are latent periods: periods that are symptom-free.

Syphilis first appears as an acute infectious disease that then appears to go away on its own. It may reemerge a short while later, only to appear to go away again. It may also come back as a chronic, non-contagious medical condition.

This means there are two distinct groups of people with syphilis – those who are infectious but may recover spontaneously, and those who aren’t infectious but won’t get better without treatment. Blood tests for syphilis in either group of people will be positive.

Syphilis used to be a leading cause of death and disability. It is believed that it was introduced into Europe from the Americas by the early Spanish explorers. It spread throughout Europe and became a condition associated with sex, and since Venus was considered the "goddess of love," it became known as venereal disease (VD – venereal is an adjective formed from Venus). There was no treatment for syphilis until 1945, when penicillin was developed. This medical condition is much rarer today due to the widespread use of antibiotics.

Over recent years the rates of syphilis in Canada have increased in both men and women, but moreso in males.

Similar to other sexually transmitted infections, infection with syphilis can increase the risk of becoming infected with or transmitting HIV infection.


In the vast majority of cases, syphilis is transmitted by sexual contact. It can be transmitted by all forms of sexual contact, including oral and anal sex, and potentially even by kissing.

Syphilis produces a painless ulcer on the body part that’s come into contact with an infected person. That sore slowly leaks a clear liquid, which contains many syphilis bacteria. If it touches someone else’s broken skin or a mucous membrane (such as the inside of the vagina), it’s likely to create a new sore – passing on the infection. These initial sores cause no pain and are often located in hidden areas, so people can transmit syphilis without knowing they have it.

Congenital syphilis occurs when a pregnant mother with syphilis passes on the infection to her baby. This can result in serious and significant health issues for the baby, including death of the unborn baby. The incidence of congenital syphilis has also increased in recent years. All pregnant women should be routinely tested for syphilis, so that if the infection is present it can be treated.

Symptoms and Complications

The initial stage of the disease is called primary syphilis. There’s usually just one ulcer, which appears 10 to 100 days (on average, one month) after infection. At first, it appears as a red dome and is where the bacteria initially multiply. It rapidly erodes to become a painless ulcer called a chancre (pronounced "shanker"). The chancre typically clears up and heals in a month or two whether the person is treated for the disease or not. A person is contagious during primary syphilis.

If the person is not treated, however, the bacteria can eventually enter the bloodstream and be carried to many parts of the body. This happens in about 25% of people who do not receive treatment for their primary syphilis. A rash can develop during this stage. It is typically seen about 6 weeks to 3 months after the chancre forms and, in some cases, can occur even though the chancre has not fully healed. The rash can get steadily worse over the next 2 months. Round red or brown spots appear on the chest, arms, and legs. What is particularly unusual about this rash is that it can also be found on the palms of the hands and soles of the feet. The rash can remain as red spots, or become pustular or scaly, but it is usually not very itchy. The rash may clear up only to be replaced by another.

There can also be flu-like symptoms such as headache, fatigue, and a mild fever. The bacteria can also get into the brain and cause meningitis. The person may experience hearing loss, balance problems, visual changes, and bone pain. Some people show signs of anemia and jaundice. This syndrome is called secondary syphilis and it can come and go for a year or two. For as long as the rash is present, a person with secondary syphilis is contagious.

In many people, syphilis stops there, even if it’s not treated. The bacteria remain but they cause no symptoms and don’t emerge to infect others. This is called latent syphilis. It may remain inactive forever, or may become active again years later.

People who aren’t treated during the primary stage have a 1 in 3 chance of developing chronic tertiary syphilis. The bacteria retreat deep into the body and are no longer contagious, but syphilis can reappear decades after the last rash of secondary syphilis. The disease poses a grave threat to the internal organs, including the brain, heart, blood vessels, and bones. Syphilis can lead to death if it is not treated.

Complications of tertiary syphilis include:

  • brain damage: Depending on which part is damaged, symptoms could range from motor effects (such as tremors) to mood disorders (such as having delusions of grandeur). Muscle weakness, pain, decreased muscle coordination, and loss of movement of the limbs are possible.
  • heart and blood vessel damage: Syphilis has a particular tendency to damage the walls of the aorta, the body’s biggest artery, which can lead to an aneurysm. This syndrome usually appears 10 to 25 years after the initial infection.
  • damage to the retina and the vital nerves and blood vessels at the back of the eye: Syphilis usually attacks both eyes. If left untreated, irreversible eye damage that may result in blindness can develop. Again, this can happen many years after the original infection.

These are just some of the most likely organs to be damaged. However, symptoms should not become this severe, since syphilis can be cured in a few days at the outset. It can be a subtle disease, however, and can go unnoticed during the primary stage.

Making the Diagnosis

Syphilis is easy to diagnose in the primary or secondary stage if there’s a visible sore or ulcer. A swab of this sore will provide bacteria that can be identified under the microscope. Otherwise, blood tests are available to confirm the diagnosis. These blood tests can be repeated after treatment to confirm that it has been successful.

Treatment and Prevention

Penicillin, given as a long-acting injection of benzathine penicillin G, is used to treat all stages of syphilis. Despite over 60 years of use, the syphilis bacterium has not yet developed resistance to this original antibiotic. For primary syphilis, one injection (usually given as half a dose into each buttock) is enough to permanently cure this disease that once claimed so many lives.

Secondary and latent syphilis are treated the same way. Most people with infectious syphilis, especially those in the secondary stage, suffer a reaction when they’re first treated. The symptoms include a sudden fever with headache, sweating, and possibly a rash. This clears up in less than 24 hours.

Penicillin stops the infectivity within a day or two, and cures the disease in 1 to 2 weeks. A person should wait until the treatment is finished before engaging in sex. If the person is allergic to penicillin, desensitization to penicillin may be necessary or another antibiotic may be substituted.

Tertiary syphilis is also treated with penicillin injections. Treatment usually requires an injection once weekly for 3 weeks.  Though this doesn’t always kill all the hidden bacteria, it does generally stop further damage. There’s no way to repair the organ damage that’s already been done, however.

It is important to keep your follow-up appointments with your doctor. Even though you may have been treated with antibiotics, treatments have been known to fail. Your doctor will do some blood tests to make sure that the antibiotics have worked and that the bacteria have been cleared away.

The best way to avoid these complications and syphilis altogether is by practicing safe sex. Wearing a condom correctly is a good first step, but standard intercourse is not the only way to get syphilis. Any mouth-to-genital contact and sometimes even mouth-to-mouth contact is enough to transmit the disease. To minimize your risk, limit your number of sexual partners and be careful who they are – ask for a syphilis (and other STI) test. If you develop syphilis, your sexual partners should be notified, tested, and possibly treated.

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