A chancre (/ˈʃæŋkər/SHANG-kər)[1] is a painless genital ulcer most commonly formed during the primary stage of syphilis.[2] This infectious lesion forms around 21 days after the initial exposure to Treponema pallidum, the gram-negativespirochaetebacterium causing syphilis, but can range from 10 to 90 days.[2] Without treatment it may persist for two to six weeks before healing.[2] Chancres transmit syphilis through direct physical contact. These ulcers usually form on or around the anus, mouth, penis and vulva.
Chancres can occur in the pharynx as well as on the genitals. Not to be confused with condylomata lata, which is seen in secondary syphilis.
Etymology
The word "chancre" (fr) means "little ulcer" in Old French. Related to the English "canker", they both come from the Latincancer, meaning "crab",[6] which is a translation from the Greek word καρκίνος (karkínos), also meaning "crab".[7]