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What are the symptoms of syphilis?

What are the symptoms of syphilis?

Updated on:
February 16, 2022

Syphilis is a bacterial infection that is most commonly caught by engaging in sex with someone who is already infected.

There are multiple stages during a syphilis infection, causing symptoms to vary over time. Every body reacts to this STI (sexually transmitted infection) differently, meaning that symptoms might develop in different orders, severity, or not at all (asymptomatic infection).

It is important to know that syphilis has a high likelihood of presenting with no symptoms. Some studies report that 50% (source) of those infected are asymptomatic. The lack of symptoms for many is why syphilis is such a common infection. However, asymptomatic infections can still be infectious.

Even though it is essential to always be on the lookout for symptoms in your body, consistent testing while you're sexually active is the best way to stay aware of your infection status.

Early symptoms of syphilis (primary stage)

If you've been exposed to syphilis, early-stage symptoms typically develop around 2 to 3 weeks after the initial infection. However, this isn't always the case. It's not uncommon for syphilis symptoms to present themselves three months after the bacteria enters the body. This early stage of syphilis is known as "primary syphilis."

Symptoms during this stage primarily include swollen glands and sores (doctors call them chancres).

Swollen glands
These are sensitive, painful lumps that are usually found around the:

  • Groin
  • Neck
  • Armpits
  • Elbows

The swelling of your glands is a common sign that your body is fighting off an infection. This swelling process can lead to other symptoms like a sore throat, cough, or fever.

Sores/ulcers (chancres)
Unlike the swollen glands, these small, open sores are typically painless and reside on the:

  • Penis
  • Scrotum
  • Vagina
  • Anus or butt
  • Mouth or lips
  • Fingers

While it's common to only have one sore, there are cases where those infected with syphilis have several on their body. These ulcers are extremely contagious and can easily be mistaken for a common blemish, ingrown hair, or a harmless bump.

They usually disappear after 3 to 6 weeks, with or without receiving treatment.

Later symptoms of syphilis (secondary stage)

These additional symptoms can develop weeks after the previous early-stage symptoms have faded away. This stage in the syphilis life cycle is known as "secondary syphilis." Around 25% of cases will progress to this stage.

These are blotchy, red rashes that can pop up anywhere on your skin. The most common locations this rash can be found include:

  • Trunk of the body
  • Palms of the hands
  • Soles of the feet

These rashes are very contagious and can spread the syphilis infection through casual contact.

Small skin growths (similar to genital warts)
These growths are often found on the anus. Unlike actual genital warts, they are caused by spirochetes (bacteria) rather than the wart virus.

Similar to the rashes previously mentioned, these growths are also highly spreadable through physical contact.

Flu-like symptoms (fatigue, headaches, joint pain, fever)
Not all symptoms experienced will make it obvious that your body is being attacked by the syphilis infection. It is common for many who are infected to equate these signs to the common cold or flu.

Hair loss
This symptom is not common, but there are documented cases (source) where hair loss is the only sign presented. This hair loss is not permanent in many cases. It can often grow again after the patient undergoes proper treatment for syphilis.

Weight loss
There are cases where men infected with syphilis have lost noticeable amounts of weight. For example, a case describes a patient that lost 6 kg only in the span of two months (source). Luckily your weight will likely revert back to its normal state after you complete treatment.

Similar to the earlier stage of syphilis, these later-stage symptoms usually pass over a span of a few weeks. But don't be surprised if you find these symptoms sporadically appearing and disappearing over multiple months.

Early latent syphilis
This is the time during the first year of infection where there are no symptoms but syphilis is replicating within the body, including the skin, and can still be transmitted to others through sexual and blood contact.

Late latent syphilis
Even if you don't present any symptoms, those infected with syphilis will continue to have it remain in their body.

This period of inactivity is known as "late latent syphilis" or the "non-infectious stage" where the syphilis infection can remain dormant for decades in certain tissues within the body.

Unfortunately, it can reactivate locally within tissue and cause irreversible damage to any part of the body, including the brain, heart, and eyes.

Serious symptoms if left untreated
Severe symptoms can result from late-stage syphilis 10-30 years after the initial infection. Even though treatment is still viable at this late stage, it won't undo the harm from these harsh side effects.

  • stroke
  • dementia
  • aneurysms
  • personality changes
  • visual problems or blindness
  • numbness
  • loss of coordination
  • meningitis
  • heart problems
  • death

What To Do if You Think You're Infected With Syphilis

Syphilis is highly and easily treatable.

Even if you've been treated for syphilis before, you can become infected again.

Only a lab test will be able to tell you if you currently have syphilis. If you believe you're infected with syphilis, the best thing to do is to seek out a local health care provider and get tested.

By collecting a simple blood sample, your doctor will be able to tell you if you're infected. Once they catch the infection, your doctor can prescribe you the appropriate antibiotic (penicillin is a typical example) to remove syphilis from your system.

Read the next article for more information regarding syphilis treatments.

Reviewed by:
Dr. Caley Shukalek

Caley is passionate about evidence-based, patient-centred care, including telemedicine that can provide high quality care from wherever a patient may choose.

He helped create Alberta's PrEP guidelines and works as a specialist in General Internal Medicine with additional training in sexual health, including HIV and sexually transmitted infections.

He holds an Masters of Public Health from Johns Hopkins University, an MD from the University of Calgary and an MSc from the University of Alberta.