Imagine having the feeling that tiny bugs are crawling on your body, that you have oozing sores and mysterious fibers sprouting from your skin. Sound like a horror movie? Well, at one point several years ago, government doctors were getting up to 20 calls a day from people saying they had such symptoms.

Afflicted patients have documented their suffering on websites and many have vainly searched for a doctor who believed them. Some doctors believe the condition is a form of delusional parasitosis, a psychosis in which people believe they are infected with parasites.