To our surprise, we found that areas of the brain associated with unpleasant or aversive emotions and memories became significantly less active during the scratching," Wake Forest University's Gil Yosipovitch, MD, says in a news release.
"Of course, scratching is not recommended because it can damage the skin. But understanding how the process works could lead to new treatments," adds Yosipovitch.
Yosipovitch and colleagues studied 13 healthy adults (average age: 28). Participants weren't itchy, but they got their lower right leg gently scratched by a researcher wielding a medical brush.
Participants got brain scans before, during, and after the scratching sessions. Those brain scans showed that certain brain areas were particularly active during scratching, while other brain regions became less active during scratching.
Those patterns may explain why scratching can feel good and be rewarding, the researchers note. But it will take more work to see if the brain behaves the same way in people dealing with itchiness (pruritus).
Their findings appear in today's advance online edition of the Journal of Investigative Dermatology.
By Miranda Hitti
Reviewed by Louise Chang
©2005-2006 WebMD, Inc. All rights reserved