Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. Recognizing its distinct skin manifestations is important for early detection and successful treatment. The bacterium can cause various skin changes that appear differently depending on the infection’s stage.
The Primary Syphilis Sore
The initial sign of syphilis is a sore known as a chancre, marking the primary stage of infection. This lesion typically appears at the site where the bacterium entered the body, usually about three weeks after exposure (10 to 90 days). Chancres are single, firm, round, and painless sores, ranging from a few millimeters to several centimeters (0.5 to 2 cm).
These sores frequently develop on the genitals (penis, vulva, cervix), around the anus, in the rectum, or on the lips or mouth. A chancre may present as an open ulcer with a clean base and sharp borders, or as a firm, raised bump. Because they are typically painless and can be located in hidden areas, chancres often go unnoticed. They heal on their own within three to eight weeks even without treatment, but the infection remains in the body and will progress if left untreated.
The Secondary Syphilis Rash
Weeks to months after the primary chancre, often after it has healed, the secondary stage of syphilis may manifest with a varied skin rash. This rash, typically appearing four to ten weeks after initial infection, is commonly red or reddish-brown, non-itchy, and can feel rough or scaly. It can be faint, making it easy to overlook, and may mimic other skin conditions.
A distinguishing feature is its frequent appearance on the palms of the hands and soles of the feet, though it can affect the torso and other body parts. Other skin lesions can develop, including moist, wart-like sores known as condylomata lata, which typically appear in warm, moist areas like the groin, armpits, or around the anus. Some individuals may also experience patchy hair loss, sometimes described as “moth-eaten” alopecia.
Late Stage Skin Lesions
In rare cases of untreated syphilis, late-stage skin manifestations called gummas can develop. These soft, tumor-like growths represent a destructive inflammatory response to the bacterium. While less common today due to effective antibiotic treatments, gummas can appear anywhere on the body, including the skin, bones, or internal organs.
Gummas can cause substantial tissue damage if left untreated, leading to deep lesions that may affect underlying bone. They are distinct from earlier primary sores or secondary rashes. These lesions highlight the long-term consequences of untreated syphilis, which can also include damage to the nervous system and heart.
What to Do About Suspected Bumps
If any suspicious bumps, sores, or rashes appear on the skin, a professional medical evaluation is important. Self-diagnosis of syphilis is unreliable due to its varied presentations, which can mimic many other conditions. Prompt medical attention is necessary if there is any suspicion of syphilis, regardless of whether the bumps are painful or itchy.
Accurate diagnosis requires specific medical tests, typically including blood tests and sometimes fluid samples from a sore. Early diagnosis and treatment are important to prevent the infection from progressing to more severe stages and serious, long-term health complications. Healthcare providers can offer proper diagnosis and guide treatment, which is generally effective with antibiotics.