Why do you scratch the itch?

When itching, you scratch your hand. This behavior helps to block the activity of nerve cells in the spinal cord, which transmit signals from the skin to the brain, out of itching.

Previous studies that confirmed part of the spinal cord (spinothalamic region) play a very important role in emotional signaling. Neurons in this area will be more active when there is an itchy agent on the skin.

The latest study of the University of Minnesota primates recorded that scratching acts to prevent the activity of spinothalamic nerve cells during the itch , meaning preventing the spinal cord from transmitting from the affected skin. stimulation to the brain. So help us feel itchy.

The mechanism seems to only occur when the body is itchy, but in normal conditions, scratching behavior does not affect the brain's activity much. Researcher Glenn Giesler hopes this result could provide more accurate evidence to help treat chronic pruritus effectively the first time. He suggested that more research is needed to have more solid scientific bases.

Professor Gil Yosipovitch, an expert in treating itching from Wake Forest University (USA), said there are many causes of chronic itching, including shingles, AIDS, gallbladder problems and Hodgkin's disease. These diseases can affect the quality of life of patients and are currently not treatable. Therefore the above findings are of great significance in treatment.

He said: 'Mechanical stimulation or use of drugs can inhibit nerve cells that create an itchy feeling but not harm the skin . This method can be used to effectively treat chronic itching '. He also stressed that pruritus is a complex phenomenon that involves factors such as emotion and physiology . 'The question is what happens to patients with chronic itching that scratching behavior can make the itching worse?'.

Dr. Paul Bays, UCL Cognitive Neuroscience Institute, acknowledges that research provides an important piece of evidence to explain the physiological mechanisms of how to reduce itching."However, it is still unclear why scratching works only with itching, but it is ineffective with pain - which is transmitted to the brain with the same mechanism."

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