Symptoms of Syphilis
The signs and symptoms of syphilis are related to the stage of the infection. The first stage involves the appearance of a painless sore on the genitals, rectum, or mouth. After the sore heals, the second stage will usually manifest with a rash. Finally, after a long period with no symptoms, the third stage can suddenly develop, causing extensive damage to the brain, nerves, eyes, or heart.
Because the symptoms of syphilis are often non-specific (or mimic other conditions like psoriasis, hemorrhoids, and canker sores), infections are sometimes missed and left untreated. It is for this reason that syphilis is often referred to as the “great imitator.”
What syphilis looks and feels like changes as it evolves, and can vary between the different types.
Illustration by Joshua Seong. © Verywell, 2018.
Primary syphilis will typically start with the appearance of a chancre anywhere from 10 to 90 days after the initial exposure (average 21 days).1 The sore will develop at the point of contact, most commonly on the cervix, vagina, penis, anus, rectum, or mouth.
There may be one or more lesions ranging in size from an eighth of an inch to an inch or more. Because the sores are painless, they can be easily missed if internalized. Swollen lymph glands can also occur, usually near the site of the infection.
Without treatment, a chancre will heal in anywhere from three to six weeks.2
If left untreated, a primary infection will progress to secondary syphilis. Symptoms typically appear within two to eight weeks of the appearance of a chancre.2 During this stage, a person may feel sick and experience fever, sore throat, fatigue, weight loss, and headache. A generalized swelling of the lymph nodes (generalized lymphadenopathy) is also common.
One of the more characteristic symptoms of secondary syphilis is a widespread, non-itchy rash on the trunk, limbs, and (most tellingly) the palms and soles of the feet.
The appearance of the rash can vary dramatically. The lesions may be flat or raised, scaly or hive-like, and they can even manifest with pus-filled blisters (pustules). Whatever the appearance, the lesions are highly contagious and can readily pass the disease to others.
Other telltale symptoms include unexplained hair loss (syphilitic alopecia) and cracked lesions on the corner of the mouth (fissure cheilitis).
Secondary syphilis can also manifest in rare, unusual, and varied ways affecting the liver, kidneys, bones, and central nervous system.
The symptoms of secondary syphilis will typically resolve without treatment within weeks or months.3
Latent syphilis is the third stage of infection marked by the relative absence of symptoms but positive blood tests. It is further divided into two stages:
Early latent syphilis is the period of less than a year from the last blood test. Secondary symptoms can sometimes relapse during the early latent phase.
Late latent syphilis is the period greater than a year from the last blood test. It can last for years and even decades with no signs of disease.
While the infection can be passed during the early latent stage, it is less likely to do so during the later stages of latency.2 The duration of latency is highly variable, and scientists are not exactly sure why.
One of the factors known to accelerate progression is HIV co-infection. On the one hand, an open chancre sore provides HIV an easy route into the body. On the other, having HIV and syphilis together increases the risk of late-stage complications even during the early stages of infection.
Tertiary syphilis is the most serious stage of infection and is characterized by three major complications:
Gummatous syphilis causes the formation of soft, tumor-like lesions called gummas. These non-cancerous lesions can cause large ulcerative sores on the skin and mouth, and erode tissues of heart, liver, muscles, bones, and other vital organs. Symptoms typically develop between three and 10 years after being infected.4
Cardiovascular syphilis can cause severe inflammation of the aorta and the development of an aortic aneurysm (the swelling and weakening of the aortic wall). It generally occurs 10 to 30 years after the initial infection.3
Neurosyphilis affects the central nervous system and usually develops within four to 25 years of an infection. While some people will remain symptom-free, others may experience severe neurological symptoms including meningitis (inflammation of the membrane surrounding the brain and spinal cord) or tabes dorsalis (a condition characterized by nerve pain, loss of motor skills, visual impairment, deafness, and incontinence). Seizures, personality changes, hallucinations, dementia, schizophrenia, and stroke can also occur.4
While the syphilis infection can be treated during the tertiary stage, any damage caused to the heart, kidneys, and other organs may be permanent and lead to end-stage organ failure. Treatment is determined by the type and extent of the damage.
Syphilis is not contagious during the tertiary stage.5
Complications in Newborns
Congenital syphilis is a serious condition in which a pregnant mother with syphilis passes T. pallidum to her developing baby.
Untreated syphilis during pregnancy can sometimes lead to miscarriage or stillbirth.
Of the babies born with syphilis, as many as two-thirds will have no symptoms during the first couple of years of life.6 If left untreated, the symptoms may include:
Liver and spleen enlargement
Petechia (purplish skin spots caused by ruptured capillaries)
Profuse nasal drip (known as syphilitic “snuffles”) with highly infectious mucus discharge
Jaundice (yellowing of the skin and eyes)
By age 2, the child may have characteristic facial or physical deformities and significant sensory impairment, including:
Blunted upper front teeth (known as Hutchinson’ teeth)
A collapse of the bony part of the nose (saddle nose)
A protruding jawbone and foreshortened upper jaw
A protruding frontal bone of the skull (frontal bossing)
Bowing of the shin bones (saber shins)
Inflammation and scarring of the cornea (interstitial keratitis)
Related death in these children is most often caused by a lung hemorrhage.
When to See a Doctor
Because syphilis symptoms are easily missed or misdiagnosed, you need to take action if you even suspect you’ve been infected.
If you are or have ever been at risk of sexual exposure—either because of unprotected sex, having multiple partners, or being HIV-positive—you need to consider getting an STD screen whether you have had symptoms or not.
Moreover, the resolution of symptoms should never be considered a sign that an infection has cleared. If in doubt, do yourself a favor and get tested. Tests are easy and can usually return results within a couple of business days.