The child always said that the buttocks itch, may be related to physiological factors, may also be due to perianal eczema, pinworm disease, contact dermatitis and other causes. 1. Physiological factors: if the child’s buttocks area of long-term poor hygiene, such as after the stool for a long time can not be cleaned up, resulting in excreta retention, the formation of local skin irritation, may cause itchy buttocks. 2. Perianal eczema: it is considered that it may be caused by environmental factors, diet, infection and other reasons, which can lead to itchy skin around the buttocks, and may also be accompanied by local redness, swelling, oozing or vesiculation and other symptoms. 3. Pinworms: usually caused by direct, indirect or retrograde infection of pinworms, can lead to itchy buttocks, especially at night, especially obvious symptoms, but also accompanied by sleep disturbance, waking up at night and other symptoms. 4. contact dermatitis: the buttocks area in contact with certain allergens or irritating substances, may lead to buttocks local skin contact dermatitis, which may cause buttocks itching, at the same time can appear erythema, pimples and other symptoms. Children always say itchy buttocks, but also for other reasons, to rule out physiological factors, it is recommended to seek medical attention as soon as possible, clear reasons, give targeted treatment.