Perianal inflammation is a suppurative bacterial infection of the apocrine glands, which often occurs in young and middle-aged people. It is characterized by nodular ulcers and even fistula formation. This disease is caused by apocrine gland occlusion and secondary bacterial infection. It is mostly caused by Staphylococcus aureus, and sometimes by infection with Streptococcus, Escherichia coli, and Proteus. It is related to excessive sweating, poor hygiene, friction, scratching, and trauma. Subcutaneous nodules are formed at the beginning, and local ulcers are formed after suppuration and rupture, and finally scars heal. At the beginning, a single or several pea-sized subcutaneous nodules are locally hemispherical, which can increase to the size of a walnut, red, swollen and painful, with mild systemic symptoms. After several weeks or months, the nodules soften, purulent in the deep, and ulcers are formed after rupture. It can also be a chronic process after a long time, or form extensive fistulas.