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.

一个极端例子是一种叫做妄想虫病心理况，人认为身体被螨虫或跳蚤滋，在皮肤上下窜动，使不停地发痒。