Syphilis is divided into congenital syphilis and acquired syphilis. Acquired syphilis is further divided into early and late syphilis, early syphilis: stage I and II, early latent syphilis. Late syphilis: late latent syphilis,, stage III syphilis includes dendritic, cardiovascular and neurological syphilis. Congenital syphilis is further divided into early and late stages, which include the features of congenital syphilis. Clinical features Incubation period: In symptomatic patients, the incubation period before the appearance of hard chancre (stage I syphilis) is 10-90 days. Stage II syphilis develops 3-6 weeks after the appearance of the hard chancre. Stage I syphilis: ulcers, usually with local lymph node involvement. Isolated, painless ulcers with a clean basal surface and hyaline plasma exudate appear near the anus and external genitalia. Occasionally, atypical presentations are seen: multiple, painful, purulent, erosive lesions that occur on the external genitalia. All ulcers in the anal and external genital area should be considered syphilitic unless other infection is proven. Stage II syphilis: bacteraemia leading to multisystem involvement and possible relapse in the second year after infection. It usually presents with non-itchy polymorphic erythema on the palms and soles of the affected hands, lichen planus, rash of mucosal skin, and often lymph node involvement. Rarely, flaky alopecia, vestibular uveitis, meningitis, cranial nerve palsies, hepatitis, splenomegaly, osteochondritis and glomerulonephritis are seen. Erythema may be pruritic and is seen especially in dark-skinned patients. Latent syphilis: serologically positive syphilis without clinical evidence of spirochete infection. It is roughly divided into early (<1 year of disease) and late (1 year of disease) stages. Late syphilis includes: syphilitic dendrites : typical nodules/plaques or ulcers; neurosyphilis: cerebrospinal vessels, brain parenchyma, asymptomatic; cardiovascular syphilis: aortitis, angina, aortic regurgitation, coronary arteriosclerosis, aortic aneurysm.