Itchy anus in a three-year-old baby may be caused by dermatitis, anal eczema or pinworms. Different causes, different treatment methods, including basic treatment, topical drug treatment or systemic drug treatment. 1. Basic treatment: children’s clothing to cotton texture is appropriate, cool, loose; to avoid excessive washing of the local skin; avoid eating spicy food during the onset of the disease; the application of emollients, and timely restoration of the skin barrier; pinworms wash the perianal area and the perineum before bedtime every night. 2. Topical drug treatment: anal itching caused by dermatitis or anal eczema, for children patients generally choose to use weak glucocorticosteroids, such as Dinaid cream. For children with pinworm disease, local pinworm ointment can be rubbed to kill worms and stop itching. 3. Systemic medication: when there is secondary bacterial infection in the anus, antibiotics are added, such as cefixime. For pinworm disease caused by anal itching, can choose mebendazole and other drugs for deworming treatment. Pediatric anal itching obvious, need to go to the hospital in time to clarify the cause of the disease, follow the doctor’s instructions standardized treatment. All of the above drugs should be used under the guidance of a doctor to avoid the wrong use of unnecessary harm.