Scientists Find Gene for Itchiness

"When we feel pain, we withdraw our hands and feet to protect ourselves from painful stimuli, to protect ourselves from being hurt. When you feel an itch, instead of withdrawing, you use your hand to scratch that area -- it's an opposite response."

Carstens agrees, pointing out that scratching can serve multiple purposes when it comes to resolving the itch.

"You put your hand on the hot stove -- your first reaction is to move your hand so you don't get burned. Pain is like a warning system," said Carstens.

"You can think of itch in the same way; it's a warning system. Only you pay attention to the itch and you direct your attention to it, see what's causing the itch, and try to brush it away."

Often, that means scratching the skin in an attempt to remove the offending bug or chemical causing the itchy feeling.

Scratching an itch is also important because it can produce a temporary pain, which serves to distract the brain in hopes that it will forget about the itch and move on to something more important.

"Not only is the scratching a protective mechanism to remove a potential source of irritation, it's also a mild form of pain, and pain suppresses the itch," said Carstens.

In Search of Pain

Chen and his group actually started out in search of a pain receptor, and instead stumbled upon this new finding.

"This itchy gene was kind of a surprise because we initially were looking for something different," he said.

"Now we can think about designing a compound that will treat itch but that will not interfere with other sensory pathways."

Many doctors see the promise of medicines developed from this gene that may help stop itching without affecting important pain receptors within the body.

"They tested to see if pain is in anyway affected, and they show there was no change," said Dr. Arjunan Ganesh, an assistant professor of anesthesiology at the Children's Hospital of Philadelphia.

This could mean that patients who are on pain medication and also experiencing symptoms of itchiness may one day be able to find relief without worrying about interactions with their pain relievers.