SAN DIEGO -- A mysterious skin disease that feels like bugs are crawling out of a person's skin and leaving a trail of worm-like fibers has doctors scratching their heads.

It's called Morgellons Disease,' and it's caused by mysterious fibers that have no DNA or living cells but supposedly poke through wounds in the skin.

It's been the subject of debate between skin doctors, many of whom can't find any scientific basis for the ailment.

However, it feels real to sufferers like pediatrician Dr. Gregory Smith, who said Morgellons cost him his medical practice and nearly cost him his sanity.

"We talked to each other and questioned our own sanity -- it seems as though some of this stuff was so odd-- that it just couldn't be real. It just could not be real." Smith said.

Oklahoma State University researcher Randy Wymore calls Morgellons a real disease but admits there's no scientific explanation for it.

"This is not some sort of an insect. They don't look like textile or environmental contaminates that are just showing up that you would find in any sort of environment," Wymore said.

But many dermatologists such as Dr. Noah Scheinfeld of Columbia University dismiss Morgellons as simply a new version of a mental disorder called delusion of parasitosis.

He said the skin rash associated with Morgellons disease is made by the patients themselves because the think they are infested with some kind of parasite or they are experiencing a sensation of some kind of parasite in their skin.

The National Morgellons Foundation doesn't state how many Americans may be suffering from the disease, but its Web site claims there are thousands.

Meanwhile, the Center for Disease Control plans to launch an investigative study of 100 people in Texas who report having Morgellons.