Syphilis can be divided into acquired (acquired) syphilis and congenital (fetal) syphilis according to the route of transmission; early syphilis and late syphilis according to the period of onset; and overt syphilis and latent syphilis according to the presence or absence of symptoms. Acquired syphilis Early syphilis: disease duration within 2 years. Stage I (hard chancre) Stage II Early latent Late syphilis: disease duration of more than 2 years. Benign syphilis (skin mucosa, bone, eye, etc.) Visceral syphilis (e.g. cardiovascular, liver, etc.) Neurosyphilis Latent syphilis Congenital syphilis Early stage (less than 2 years old) Late stage (greater than 2 years old)