Scratching an itch sometimes takes care of the itch, but sometimes it makes it worse. Most of the time good results are obtained, but when things go wrong, they can on rare occasions go extremely wrong. This is true whether we're thinking literally or figuratively, of course. As an idiom, "Scratch That Itch" generally suggests that it's okay to go ahead and satisfy a need or desire. Often this is good advice, but frequently in life there are prohibitions against satisfying certain needs or desires and so the possible ramifications of "scratching an itch" should be considered before the actual scratching begins! This is particularly true if feelings of aggravation cause someone to want to solve a problem in a way that might cause harm to others. Complicated social situations seldom have simple solutions and so "scratching that itch" should not be done without a little careful forethought. Acting compulsively can have bad consequences and so scratch judiciously!