Syphilis is an infectious disease caused by the spirochete Treponema pallidum, which penetrates broken skin or mucous membranes. Transmission occurs most frequently by sexual contact. Congenital syphilis can be transmitted to the fetus during any stage in pregnancy. Syphilis is widespread in the United States and primarily involves sexually active adults between 20-29 years of age. Syphilis has several stages. In the primary stage, painless sores, called chancres, appear approximately 2-3 weeks after initial exposure. Some individuals with primary syphilis may not notice chancres nor have symptoms associated with them, in particular if the chancres are located in the rectum or cervix. In about 4 to 6 weeks chancres will usually disappear. Approximately one-third of untreated individuals will progress to the second stage: secondary syphilis. This usually occurs at about 2 to 8 weeks after the appearance of the original chancre in some cases the chancre may still be present. Secondary syphilis is the stage where the bacteria have spread in the bloodstream and have reached their highest numbers. The most common symptoms include skin rash which can be varied in appearance, yet frequently involves the palms and soles, in addition to lesions in the mouth, vagina, penis (mucous patches), swollen lymph nodes, and fever. This stage is the most contagious stage of syphilis. It usually resolves within weeks to a year. A latent phase follows, which may last for years and is characterized by the absence of symptoms. The final stage of syphilis is called tertiary syphilis and is characterized by brain or central nervous system involvement (neurosyphilis), cardiovascular involvement with inflammation of the aorta (aortitis or aneurysms), and gummatous syphilis (destructive lesions of the skin and bones).
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