One extreme example is a psychological condition called delusory parasitosis where people believe their bodies are infested with mites or fleas scurrying over and under their skin, making them itch incessantly.

一个极端的例子是一种叫做妄想性寄的心理况，人们们的身体被螨或跳蚤滋，在们的皮肤上下窜动，使们不停地发痒。