As long as your hands are clean and you don't scratch so hard that you break the skin, scratching offers relatively harmless itch relief for people with normal skin. "Itch probably evolved as one of the skin’s 'radar systems' to ensure that we scratch away bugs, parasites, and other potentially harmful stuff," says Jeffrey D. Bernhard, M.D., a professor at the University of Massachusetts Medical School, in Worcester. While scratching can aggravate chronic skin conditions, such as atopic eczema (moisturize the skin instead), it can inhibit your brain's perception of a minor itch, like a fleabite, for "a couple of minutes or sometimes hours," says Gil Yosipovitch, a professor of dermatology at Wake Forest University School of Medicine, in Winston-Salem, North Carolina. (Bet you're itchy now — aren't you?)