Why Does Scratching Make You Itch More? Science Has An Answer

From dry skin to mosquito bites, there are a million little reasons why we itch. But sometimes, scratching an itch can make you feel, well, itchier -- and a group of scientists has a possible explanation for why this happens. On Wednesday, researchers at Washington University School of Medicine in St. Louis published a study which found that scratching an itch can cause minor pain, leading the brain to release serotonin -- the "happy" chemical that helps regulate mood -- which can sometimes make an itch feel more intense. "The problem is that when the brain gets those pain signals, it responds by producing the neurotransmitter serotonin to help control that pain,” senior investigator Zhou-Feng Chen, PhD, who's also the director of Washington University’s Center for the Study of Itch, explained in a written statement. “But as serotonin spreads from the brain into the spinal cord, we found the chemical can ‘jump the tracks,’ moving from pain-sensing neurons to nerve cells that influence itch intensity.” (Story continues below.) Scientists involved with the study bred a strain of genetically engineered mice that lacked serotonin. When injected with itch-causing chemicals, these mice didn't scratch as much as mice with the ability to produce serotonin. But as soon as the genetically engineered mice were injected with serotonin, the scratching began. This finding doesn't exactly translate into a "cure" for itches. For one thing, living a serotonin-free life isn...
Source: Science - The Huffington Post - Category: Science Source Type: news