Sexually transmitted diseases, referred to as STDs, are a group of infectious diseases that are mostly transmitted through sexual intercourse. Curing microorganisms include viruses, chlamydia, mycoplasma, spirochetes, bacteria, fungi, etc. Different pathogens cause different STDs. Sexually transmitted diseases usually directly damage the genital organs, and the area around the anus is also a good site for sexually transmitted diseases because of its warm and moist conditions. This is especially true for people who have abnormal anal sex. Sexual confusion is the main and direct cause of STD transmission. In addition, STD can also be transmitted through other means, such as: blood, blood transfusion, injection of blood products, and the use of the same syringe; and then through kissing, sharing household items like towels, bath towels, bathtubs, sitting toilets, underwear, shaving knives, toothbrushes, etc. can also cause infection. Infection may also occur when a healthy person comes into contact with the patient’s secretions and fails to wash them in time. There are several common sexually transmitted diseases around the anus: a. Syphilis Syphilis is a chronic systemic infection caused by the syphilis spirochete sexually transmitted diseases. According to the route of infection can be divided into congenital syphilis and acquired syphilis; according to the stage of disease can be divided into early syphilis (including a syphilis and two syphilis) and late syphilis. Syphilis can also involve internal organs in addition to causing a generalized skin rash. In the perianal area, stage I chancre and stage II flat warts can occur. The hard chancre occurs mainly in the genital area, but can also occur on the perianal skin. The hard chancre is the main manifestation of stage 1 syphilis, or early syphilis. The rash appears as painless hard erythema, vesicles or ulcers, usually 1-1.5 in size, with rounded edges and neatly raised, and surrounded by inflammatory red circles, hard to touch as hard as cartilage, hence the name hard chancre. The patient usually has no conscious symptoms, no pain, no itching, and no pain when squeezed. The chancre is usually single, occasionally 2-3. In this period, syphilis seropositivity is often negative, therefore, a negative seropositivity does not exclude syphilis. Lichen planus is a specific skin manifestation of the second stage syphilis rash. They usually occur on moist, friction-prone areas of the body, and they are more common around the anus because of this characteristic. The rash is proliferative and hypertrophic, protruding from the skin and fusing with each other to develop a redundant, non-tipped plaque that may be vesiculated and exuding, with a large number of syphilis spirochetes on the surface, and is highly contagious. The patient is usually asymptomatic, or occasionally has mild itching and pressure pain, and may have pain when defecating. This is one of the most common sexually transmitted diseases, the perineum is warm and moist, the onset of more. The incubation period of condyloma acuminatum is generally 3 weeks to 8 months, with an average of 3 months. The actual fact is that you can find a lot of people who are not able to get a good deal on a lot of things. The actual fact is that you can find a lot of people who are not aware of the fact that they are not able to get a lot of money. The surface of the wart can break down and bleed due to friction. There is no cure for this disease. Before the onset of the disease, there may be a local burning and pins and needles sensation. The rash appears as clusters or scattered blisters around the anus, the size of rice grains to green beans, which can form vesicles or ulcers when they break down and become painful. Most of the perianal sexually transmitted diseases have no obvious symptoms, so it is not easy to attract the attention of patients, and it is also easy to be confused with other diseases of the anus and delay the disease, so patients should go to the hospital in time.