Syphilis, which the bacterium Treponema pallidum causes, is a form of sexually transmitted infection. There are four stages of syphilis. The infection can be serious or cause severe complications without treatment.
Primary syphilis includes the first sign of syphilis, which is typically a small and painless sore near the genitals, anus, or mouth, near the site of infection.
If a person does not seek treatment after noticing these first signs appear, syphilis may progress to the second stage.
According to one 2016 study that appeared in the journal Head and Neck Pathology, around 25 percent of people who have an infection of the Treponema pallidum bacterium will develop secondary syphilis.
At the secondary stage of the disorder, syphilis is still curable with medication. If the person does not work to treat the condition, however, it may progress to further stages, where medical treatment is more difficult or impossible.
The most common sign of secondary syphilis is a rash that does not itch or cause pain. The rash may appear on one part of the body or be more widespread.
Secondary syphilis can cause the lymph nodes to swell.
Primary syphilis typically shows up as a single, open sore around the genitals, mouth, or anus. The sore, which doctors call a chancre, is painless.
It is a small, firm bump-like sore that appears anywhere from 10 to 90 days after the infection occurs. The Centers for Disease Control and Prevention (CDC) note the average time for the first symptom to appear is 21 days.
The initial sore may also appear on the inside of the mouth, anus, or vagina, making detection difficult until the secondary stage.
Secondary syphilis occurs as the infection progresses. More lesions may appear on the mouth, anus, or vagina during this stage.
Some people may also experience a rash. The characteristic rash from secondary syphilis appears as rough, reddish-brown spots that usually appear on the palms of the hands or bottoms of the feet.
The rash is typically painless and does not itch. It may appear in one area of the body or spread to multiple areas.
However, rashes may have different appearances and occur in many locations on the body.
For instance, some people may experience condyloma lata, which are large, grayish-white lesions that appear in warm and damp environments such as the armpits, mouth, or groin. Sometimes, it is very faint, and a person may hardly notice that they have a rash.
Other symptoms that may help doctors diagnose secondary syphilis include:
muscle aches and pains
swollen lymph glands
patchy hair loss
Symptoms will disappear with or without treatment. However, without treatment, the infection will simply become latent, or hidden.
After a time, latent syphilis may lead to late-stage, or tertiary, syphilis, which may harm entire organ systems and possibly lead to death.
Treating syphilis as soon as possible is important to avoid potential for complications or the spread of the infection.
Syphilis is a sexually transmitted infection (STI), so sexual contact may expose people to the infection.
The CDC note that in recent years, 58 percent of new primary and secondary syphilis diagnoses occurred in men who have sex with men. However, syphilis is still prevalent in sexually active heterosexual couples and in females.
Syphilis passes between people through direct contact with syphilis sores. These sores typically occur in areas that have to do with sexual contact, such as the: