Syphilis is a sexually transmitted disease that is common in clinical practice and can be transmitted in a number of ways, such as through sexual contact, placenta-placenta transmission and blood products. If transmitted through sexual contact, the first site of syphilis is often the site of sexual contact, and the vast majority of chancre lesions, i.e. stage 1 syphilis, occur mainly on the pubic area, with the coronal groove, glans, penis, prepuce and scrotum in that order in males. In women, it often occurs on the labia majora and minora, or labial union, and in a minority of cases, the chancre occurs outside the pubic area. Common sites include those involved in sexual behavior, such as the breast area, especially the nipple and areola, followed by the anus, lips, fingers and other oral mucous membrane areas. Infection with the spirochete syphilis initially presents clinically as stage I syphilis, usually with hard ulcers, mainly in the genital area or at the site of sexual contact, often accompanied by enlarged regional lymph nodes.