Why Scratching an Itch Makes It Worse --- Why does scratching an itch only make it worse? As it turns out, a brain-signaling chemical released in response to scratching has some unintended effects, scientists say. -- Scratching an itch provides a bit of relief at first. It works because scratching causes mild pain, so the neurons in the spinal cord transfer pain signals instead of itch signals up to the brain. -- But then the brain releases a neurotransmitter called serotonin to dampen the pain, and in a new study, researchers found that this serotonin release also activates certain neurons in the spinal cord, which creates more itching sensations. -- The researchers conducted their work in mice, but the same vicious cycle of itching and scratching could be going on in people as well, they said. -- "The problem is that when the brain gets those pain signals, it responds by producing the neurotransmitter serotonin to help control that pain," co-author Zhou-Feng Chen, director of Washington University's Center for the Study of Itch, said in a 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." -- More, http://www.msn.com/en-us/health/medical/why-scratching-an-itch-makes-it-worse/ar-BBcKRLu