The glans mouth has a purple small bag may be sebaceous cysts, acute superficial circumcision or glans pearl rash and other causes, need to be specifically analyzed. 1. Sebaceous cysts: a purple pouch in the glans may be caused by sebaceous cysts. There are sebaceous glands distributed in the glans, and if the cleaning is not in place, the sebaceous glands may be blocked and sebaceous cysts may appear. 2. Acute superficial circumcision glans: glans mouth has a purple bag may be acute superficial circumcision glans caused by the patient may glans skin mucous membrane has been a small injury, and then due to the cleaning is not in place to lead to infection, which in turn caused acute superficial circumcision glans. 3. glans pearl rash: glans mouth has a purple bag may also be glans pearl rash caused by glans pearl rash, glans pearl rash is mainly due to the patient does not pay attention to personal hygiene leading to bacterial growth and caused by a benign proliferative diseases, can be sent through the excision of pathological examination, treatment. The glans mouth has a purple small bag may also be other reasons, it is recommended that patients find themselves in a similar situation, timely medical perfect relevant examination, standardized treatment. In addition, drugs may cause side effects symptoms, medication should be used under the guidance of a doctor, do not blindly use drugs.