Syphilis is a bacterial infection caused by Treponema pallidum, typically transmitted through direct contact with a syphilitic sore during sexual activity. If left untreated, the infection progresses through distinct stages, each marked by different signs and symptoms. Early detection and treatment are important to prevent the infection from advancing and causing damage to various organ systems.
The Initial Stage of Infection (Primary Syphilis)
The progression of syphilis begins with the primary stage, following an incubation period of 10 to 90 days after initial exposure. The characteristic lesion is the chancre, which develops where the bacteria entered the body. This sore is usually firm, round, and painless, often appearing in or near the mouth, genitals, or anus.
Because the chancre is painless and can be hidden, people often do not notice it. Even without treatment, this primary lesion spontaneously heals within three to six weeks. However, the Treponema pallidum bacteria remain in the body and continue to multiply. The healing of the chancre signals the end of the primary stage and the start of the next phase.
Timeline and Defining Characteristics of Secondary Syphilis
Secondary syphilis generally begins 4 to 10 weeks after the primary chancre first appeared, often as the chancre is healing. This stage marks the widespread dissemination of the bacteria through the bloodstream to various parts of the body.
The defining sign is a non-itchy skin rash that can appear anywhere on the body, often presenting as rough, reddish-brown spots. A classic presentation involves the rash being visible on the palms of the hands and the soles of the feet. The rash may also be subtle, meaning some people may not realize they have developed a skin eruption.
Common Manifestations of Secondary Syphilis
The systemic infection often leads to other signs that may be mistaken for common illnesses. Many people experience “flu-like” symptoms, including:
- Low-grade fever
- Malaise (a generalized feeling of being unwell)
- Sore throat
- Headaches
Swollen lymph glands (lymphadenopathy) are also common during this stage. More specific lesions may develop, such as moist, wart-like patches called condylomata lata. These highly infectious patches often appear in warm, moist areas like the groin or under the arms. Some people may also notice patchy hair loss, which can present as a “moth-eaten” appearance on the scalp, eyebrows, or eyelashes.
The Subsequent Stages (Latent and Tertiary Syphilis)
If secondary syphilis remains untreated, its symptoms eventually resolve, but the infection persists. The disease enters the latent stage, a period where the bacteria remain present but there are no visible signs or symptoms. This stage can last for many years and is divided into early and late phases based on the duration of the infection.
In untreated cases, the infection may progress to the tertiary stage, sometimes decades after initial exposure. Tertiary syphilis can cause severe damage to major organ systems. This advanced stage is associated with serious complications affecting the heart and blood vessels, the brain and nervous system, and the formation of destructive lesions called gummas.