It usually takes six to eight weeks for stage 1 syphilis to progress to stage 2 syphilis. Stage I syphilis manifests itself as a hard chancre, which can subside on its own without treatment, but it continues to travel throughout the body through the lymphatic system, causing systemic infections. If the patient is not careful, after six to eight weeks of incubation, the manifestation of stage II syphilis will appear, with erythema on the trunk and limbs, or palmoplantar erythema, or some flat warts on the perianal area and vulva. However, the time varies from patient to patient. It should be noted that in some patients, there is no obvious time interval between stage I syphilis and stage II syphilis, the chancre of stage I syphilis has not disappeared, and the rash of stage II syphilis has already occurred, so the interval between the two cannot be determined.