The anal crevice grows some yellow things, may be caused by perianal eczema, perianal abscess and other reasons, need to analyze the specific causes. 1. Perianal eczema: it is the eczema that occurs in the skin around the anus, which can appear symptoms such as red spots of different sizes and yellow blisters, and the most significant symptom is itching. 2. Perianal abscess: It is a purulent infection of the soft tissues around the anorectal canal and rectum. Most of the perianal subcutaneous abscesses are located in superficial places under the skin around the anus, resulting in the appearance of a yellow foreign body, and the main symptom is persistent pain around the anus. There are many reasons for this abnormal situation, you should go to the hospital in a timely manner, improve the relevant examination to clarify the cause of the disease, under the guidance of the doctor to give symptomatic treatment, to avoid causing delays in the condition.