Background
Syphilis is an infectious venereal disease caused by the spirochete Treponema pallidum. Syphilis is transmissible by sexual contact with infectious lesions, from mother to fetus in utero, via blood product transfusion, and occasionally through breaks in the skin that come into contact with infectious lesions. If untreated, it progresses through 4 stages: primary, secondary, latent, and tertiary. The image below depicts the characteristic chancre observed in primary syphilis.
Syphilis. These photographs depict the characteristic chancre observed in primary syphilis. Used with permission from Wisdom (Left) A. Color Atlas of Sexually Transmitted Diseases. Year Book Medical Publishers Inc; 1989. (Right) Centers for Disease Control and Prevention
See 20 Signs of Sexually Transmitted Infections, a Critical Images slideshow, to help make an accurate diagnosis.
Also see the Clues in the Oral Cavity: Are You Missing the Diagnosis? slideshow to help identify the causes of abnormalities of the oral cavity.
Syphilis has a myriad of presentations and can mimic many other infections and immune-mediated processes in advanced stages. Hence, it has earned the nickname “the great impostor.” The complex and variable manifestations of the disease prompted Sir William Osler to remark, “The physician who knows syphilis knows medicine.”
Many famous persons throughout history are thought to have suffered from syphilis, including Bram Stoker, Henry VIII, and Vincent Van Gogh. Since the discovery of penicillin in the mid-20th century, the spread of this once very common disease has been largely controlled, but efforts to eradicate the disease entirely have been unsuccessful.