Why Do Itches Itch?

Drop those hands. It's more than an itch that's keeping you scratching

By Gregory Mone Posted 01.31.2008 at 4:51 pm 1 Comment

Reporting in the Journal of Investigative Dermatology, Wake Forest University researchers say they've solved part of the mystery of why it feels so good to scratch an itch, even when you know it's no longer helping. (This follows news released this summer that scientists may have found a gene that could determines one's propensity for scratching an itch.)

The team subjected 13 study participants to repeated scratching while monitoring their brain activity with an MRI machine. Scratching effectively dampened the activity in areas of the brain associated with unpleasant feelings. But it also boosted activity in brain areas linked to compulsive behaviors, which may explain why we can't stop. The participants in the study weren't subject to an itching sensation, though, so there may still be some questions to resolve.

Previous Article: This Germ Could Save Your Life

Next Article: Bye-Bye Bandwidth

Want to learn more about breakthroughs in electronics, medicine, nanotech, and more?
Subscribe to Popular Science today, for less than $1 per issue!

1 Comment

Link to this comment

eshavm

06/29/09 at 5:59 pm

As someone who has scratched plenty of itches, I can say this rings true to me. Originally I heard that itches were the body's way of telling its owner that some top-layer skin needs to come off (which may be partially true) but not all itches are created equal either, so there has to be plenty of brain activity going on with scratching as well. With athlete's foot, for example, I could scratch an area until it's bleeding without feeling anything but ecstasy (until the next day of course) whereas scratching is both painful and damaging as a hemorrhoids treatment (http://www.dermaremedies.com/hemorrhoids-removal-hemroids-treatment.html) from the first touch. Scalp itches tend to be in the middle, as they seem to go away almost immediately with a good scrape or 2.

Science

+ More Photo Galleries

June 2013: American Energy Independence

Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.