The initial sign of a syphilis infection, which can take two to three weeks to appear, is a painless bump on the genitals, mouth, rectum, or skin. Swollen lymph nodes around the bump might also be a symptom.
During the secondary phase of syphilis, which occurs four to eight weeks after the first phase, a person might experience a rash. A syphilis rash can be noticeable or faint.
This article will provide an overview of what a syphilis rash looks like, diagnosing and treating a syphilis rash, and additional signs of syphilis.
Identifying a Syphilis Rash
There are several symptoms that can help identify a syphilis rash. A syphilis rash can disappear on its own or disappear and reappear for up to two years. However, regardless if a rash remains or disappears, the bacterium that causes syphilis remains in the body.
Appearance
A syphilis rash usually appears:
Dark brown or redFlatEither very visible or faintSpotty
In some cases, syphilis can look like rashes from other conditions. A syphilis rash can also appear:
PimplyBlisteryClustered
Location
A syphilis rash can be found on:
The palms of the handsThe soles of the feetOther areas of the body
Feel
A syphilis rash usually feels flat and rough.
Other Conditions that Look Similar
Since a syphilis rash can be faint and located on other parts of the body aside from the feet and hands, it can mimic other conditions. This can make diagnosis challenging.
A rash is most likely to appear about four to eight weeks after the primary stage when a painless bump and lymph node swelling can appear. This occurs about six to 10 weeks after the initial infection.
The following are some conditions that syphilis can be confused for:
Genital or oral herpes: A viral STI that can result in sores in the same areas that syphilis can infect Viral rash: A rash caused by a viral infection that can appear and disappear Medication allergy: A rash that could be a side effect of or reaction to a medication Psoriasis: An autoimmune disorder in which the body overproduces skin cells Sarcoidosis: A rare disorder of swollen tissues, often around the lymph nodes Thrush: A yeast infection that can affect the genitals and other areas
Are There Tests to Diagnose Syphilis?
Syphilis is usually diagnosed with a blood test. At times, a spinal fluid test is conducted. There might be a second test to confirm a syphilis infection if the blood test is positive.
There are also at-home syphilis tests, which entail taking a sample at home and mailing it to a lab for testing.
How to Treat a Syphilis Rash
Syphilis is treated with antibiotics like penicillin.
Syphilis treatment also includes:
Blood tests at three, six, 12, and 24 months after treatment to check if the bacterium is still presentAvoiding sexual contact when sores are presentUsing condoms until follow-up tests are completeTreatment for any sexual partners of a person who has syphilis symptoms, a diagnosis of syphilis, or another STI
Additional Signs of Syphilis
The secondary stage of syphilis includes several other possible symptoms, including:
Wartlike lesions around the genitals, mouth, vagina, penis, or skin folds that can be like blisters that sometimes leak fluidFeverLoss of appetiteMuscle and joint painSwollen lymph nodesChanging visionHair loss
In cases in which syphilis affects the nervous system (the system of the brain, spinal cord, and its nerves), a person might experience:
Stiff neckHeadacheHearing lossReflex issuesParalysis
Summary
Syphilis is a bacterial infection usually transmitted through sexual contact. The first, or primary, stage of syphilis begins two to three weeks after infection. Symptoms of the primary stage are a painless wartlike lesion at the mouth, genitals, anus, or another part of the body and swelling around the wart.
The secondary phase of syphilis includes syphilis rash, which usually appears as rough, dark red or brown spots on the palms or the soles of the feet. At times, syphilis rash can be faint or appear on other parts of the body.
Diagnosing syphilis usually requires a blood test, and it’s usually treated with an antibiotic. Other signs of syphilis include warts, fever, loss of appetite, and muscle pain.
A Word From Verywell
While the first symptoms of syphilis—a painless wart and swelling lymph nodes—can seem harmless and disappear, syphilis remains in the body until it’s treated.
Waiting for the secondary stage of syphilis, which is when the syphilis rash appears, to self-diagnose or to get treatment is not an effective way to address this STI. This is because a syphilis rash can be faint or mistaken for other disorders.
Considering that syphilis can be cured by a round of antibiotics, getting tested and seeking treatment can be a simple process. If you don’t feel comfortable testing for an STI at a clinic, there are at-home tests available for extra privacy.
