system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Whenever you have a condition that makes you itchy (e.g. bug bite, dry skin, fungus), scratching typically makes the problem worse. So why is our urge to scratch so strong?
gpt
First instinct is to get rid of whatever is biting you which is an advantage (slapping it etc.), irritating the surface can actually bring white cells and other defence mechanisms to the site of the injury. Finally the normal (pre clean plumping) way of cleaning a wound is for blood from the inside of the body to wash away any dirt or other things at the site of the problem.