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Got the itch? Urge to scratch may be contagious

By Randy Dotinga

We all know that yawns are contagious, and even the word in print can be enough to inspire one. (Sorry! Also: Yawn, yawn, yawn.) Now, a new study suggests that we live in a real-life "Itchy & Scratchy Show": We can spread itching to each other, too, and those who already have skin problems are most susceptible to scratchy suggestion.

This may not sound like the world's most important research. But many people have severe and torturous itching conditions, like eczema, that aren't easily relieved by medication. "There is a major component of suffering [from unrelieved itching]," says study co-author Dr. Gil Yosipovitch, a professor of dermatology at Wake Forest University School of Medicine. "If we understand this phenomenon, we can learn how better to treat these patients."

For sure. Many of us have experienced the misery of the itch we can't scratch. And the satisfying pleasure of finally reaching that itchy out-of-the-way spot.

Why we itch in the first place is still a bit of a mystery, but one thing is clear: plenty of living things scratch themselves. "Most animals with two legs and four legs probably itch in the course of their lives," Yosipovitch says. Dogs may be the itchiest, given how much they like to scratch. Even fish may do it too.

Seriously? Fish? "I can't prove it but if you look carefully in the aquarium, some fish go and rub themselves against the wall," he says. "I suspect that's their way of scratching the itch."

From a biological perspective, itching may have evolved as a way to alert us to a threat like a potentially dangerous bug, allergen or plant, says study co-author Dr. Alexandru Papoiu, a dermatology instructor at Wake Forest. "It's signaling that there's an intruder or aggression."

In the new study, the authors followed up on previous research suggesting that some people are more prone to develop itches when they see other people scratching. The Wake Forest researchers gathered 25 people, including 11 of whom suffered from an itchy condition called atopic dermatitis, and placed either non-itchy saline solution or an itchy substance on their forearms. Then the subjects watched videos, some of which featured people scratching their left forearms.

Among those with dermatitis whose own arms had been made itchy, those who watched the itchy videos scratched twice as long as those who watched the non-itchy videos. In other words, watching itchy people made existing itches seem even worse.

Meanwhile, itchiness came out of nowhere -- when they had nothing itchy on their arms -- in nine of the 11 people with dermatitis who watched itchy videos. That only occurred in six of the 14 healthy people.

"The patients who have chronic itch are more susceptible to these visual cues," Yosipovitch said.

Is it possible to avoid contagious itching? Good luck with that. "It is hard to escape your own mind," Papoiu says. "This response appears to emerge from (or within) deep layers of our nervous system controlling our automatic behavior."

However, he says, we may be able to immunize ourselves from suggestion through meditation, relaxation and biofeedback.

If that works for you, let us know. We'd like to try it with that yawning thing. (Oops. Sorry again!)

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