Itching of the anal opening at night when sleeping needs to be alerted to whether it is caused by parasitosis, which is a series of diseases caused by the invasion of parasites into the human body, the severity of symptoms depends mainly on the number of parasites invading the body and the resistance of the host itself, etc., of which pinworms are most likely to occur in the perianal area, mainly because pinworms invade the body and move around the anorectal area for a long time. Especially at night when resting on one’s back with the anal opening facing downward and in a lower position, pinworms will crawl out of the anus for egg-laying activities, and the stimulation of the perianal skin is greatly enhanced, and the patient will feel obvious or even intense itching at the anal opening. Treatment can be oral mebendazole or Enboprimonium to kill the worm, and need to wash the anal opening with soap and water more often, and disinfect and expose to high temperature the foreign body that is attached to the body, so as not to leave behind the eggs of the worm recurrent infection.