Syphilis is a chronic sexually transmitted disease caused by Trepenema pallidum. Syphilis is mainly infected by sexual intercourse (accounting for 95 % ). In some cases it is infected by kiss, breast feeding, surgery, blood transfusion and indirectly by clothes, shaver, cigarette holder, and medical instruments, and can also be infected from the placenta to the next generation to cause placental syphilis (congenital syphilis). Syphilis in the early stage invades mainly the skin and mucous membrane, and syphilis in the late stage attacks also various tissues and organsof the whole body, besides the skin and mucous membrane, to cause miscellaneous symptoms and signs.

Syphilis belongs to the categories of "Chancre Sore", "Fungus Boil" and "Bayberry Sore" in Chinese medicine. Among them,"chancre sore" refers mainly to hard chancre. "Bubo" refers to inguinal lymphadenectasis accompanied by chancre. "Bayberry Sore" refers to phase II syphilis. "Accumulated Toxin of Bayberry Sore" refers to phase III syphilis, mainly manifested by the typical symptoms of nodular skin rashes or mucosal and skeletal syphiloma. "Infantile Remnant Toxin" refers to placental syphilis.