Have you ever wondered why scratching an itch feels so good?
Well, researchers at Wake Forest University Baptist Medical Center in North Carolina may have finally answered that burning question.
“Our study shows for the first time how scratching may relieve itch,” said lead author Dr. Gil Yosipovitch in a news release.
“It’s important to understand the mechanism of relief so we can develop more effective treatments. For some people, itch is a chronic condition that affects overall health.”
For the study, researchers used functional magnetic response imaging (MRI) technology to monitor 13 healthy volunteers while they scratched on their lower leg with a small brush. The scratching went on for 30 seconds and was then stopped for 30 seconds — for a total of about five minutes.
“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,” said Yosipovitch. “We know scratching is pleasurable, but we haven’t known why. It’s possible that scratching may suppress the emotional components of itch and bring about its relief.”
The reduced brain activity occurred in the anterior cingulate cortex, an area associated with aversion to unpleasant sensory experiences, and the posterior cingulate cortex, which is associated with memory. When participants reported that the scratching felt most intense, activation in these areas was lowest.
“This is the first real scientific evidence showing that itch may be inhibited by scratching,” he said. “Of course, scratching is not recommended because it can damage the skin. But understanding how the process works could lead to new treatments. For example, drugs that deactivate this part of the brain might be effective.”
The work is reported online in the Journal of Investigative Dermatology and will appear in a future print issue.