NewsNeuroscienceScratching an itch is so good, and so badThe motion kicks off inflammation but may also combat harmful bacteria Scratching an itch feels so good, but it may make inflammation worse, a study of mice suggests.FotoDuets/GettyBy Laura Sanders1 hour agoScratching an itch can bring a contradictory wave of pleasure and misery. A mouse study on scratching, reported in the Jan. 31 Science, fleshes out this head-scratching paradox and could point out ways to better curb pernicious itch in people.First, the bad news: Scratching itchy ears led to a round of inflammation. Itch-provoking substances, such as the oil in poison ivy, activate mast cells, immune sentries that release itch signals and kick off inflammation. But so does scratching, the new study suggests. The act of scratching is actually triggering the inflammation by synergizing with mast cells to make them more effective, says study coauthor Daniel Kaplan, a dermatologist and immunologist at the University of Pittsburgh.