Itching in the morning at the anal opening is due to pinworm infection, the human body is the only host for pinworms, and through contact with pinworm-infected patients is also the only source of infection, pinworms infections are self and allogeneic infections, contact with contaminated eggs of food, toys in the passage of the mouth, nose and inhalation will lead to the eggs of the worm pharyngeal infection occurs. About 1/3 of pinworm infections are completely asymptomatic, but 1/3 of pinworm patients tend to have itching in the anal area due to the toxic substances produced by the pinworms and mechanical irritation. The itching at night is so severe that it interferes with sleep and causes children to cry and be upset. The itching in the anal area can lead to peeling of the skin in the anal area, rashes and eczema that can lead to suppurative infections, and the localized itching is made worse by the fact that the pinworms crawl out of the anus in the morning to lay their eggs.