Syphilis is a sexually transmitted disease caused by infection with the syphilis spirochete and can be diagnosed by symptoms and ancillary tests. Because its symptoms are similar to those of many diseases, it is known as a “universal imitator”. To confirm the diagnosis, a blood test is required, namely a positive RPR (Rapid Plasma Reactive Protein Ring Card Test) and TPPA (Syphilis Spirochete Gelatin Particle Agglutination Test). The symptoms of different stages (stage I, II and III) are as follows: 1. Stage I syphilis: typical presentation of a single chancre (moderately hard, painless, non-pruritic skin ulcer); 2. Stage II syphilis: widespread erythematous papules on the trunk and extremities and even all over the palms and feet, and even other polymorphic rashes; 3. Stage III syphilis: automatic entry into stage III two years after infection, nodularity may appear syphilis rash, syphilis dendritic swelling (soft, non-cancerous growth), bone and joint, eye and heart disease, etc. In addition, if the patient is asymptomatic after infection with syphilis or the symptoms have disappeared and there are no other manifestations except for positive syphilis serology, it is called latent syphilis and may be maintained for several years. The RPR titer test should be done before syphilis treatment, and the titer change between the two tests should be more than two dilutions to determine the titer decrease. The RPR test should be repeated monthly for the first three months after regular treatment, then every three months, and every three months or every six months for the second year to observe the changes between the current and the previous ones. Therefore, the follow-up observation of syphilis patients after treatment is usually in the period of 2-3 years. If the RPR titer of each test shows a decreasing trend, it indicates that the anti-syphilis treatment is effective. If the results of three or four consecutive tests are negative, the patient is considered to be cured of syphilis.