The baby’s body is in the stage of growth and development, all parts of the body immune organs are not yet fully developed, in addition because the baby’s skin is sensitive and fragile, especially the skin near the perianal area, so babies are more likely to be infected with bacteria than adults. Specific reasons are as follows: 1, diaper rash: that is, the baby’s diaper wrapped parts of the skin will appear inflammatory lesions, mainly manifested in the buttocks and diaper contact area skin redness, swelling, and even ulceration, infection; 2, perianal eczema: that is, eczema occurs in the perianal area. Eczema is a general term for dermatitis-type skin diseases, generally characterized by intense itching, local redness of the skin, severe exudates. There are many causes of perianal eczema, which are related to factors such as diet, bathing and clothing; 3. Perianal inflammation: it is mainly caused by bacterial infection. Stool contains a lot of bacteria, if you don’t pay attention to cleaning after the disease, the perianal area is easy to cause infection and perianal inflammation; 4, perianal abscess: mainly due to sinus infection. In the presence of perianal abscess, it is recommended to go to the hospital for examination and do the appropriate treatment.