Despite the saying “happiness is having a scratch for every itch,” itching often makes the itchy skin condition worse. So why is the instinct so strong? In a study with mice, researchers from the University of Pittsburgh uncovered why scratching worsens inflammation and swelling—and why humans and other animals may have,

New research published in the journal Science uncovers how scratching aggravates inflammation and swelling in a mouse model of a type of eczema called allergic contact dermatitis.

Scratching isn’t just a bad habit — it’s an immune defense mechanism. While it fuels inflammation, it also helps fight infections by drawing immune cells to the skin. Scientists have uncovered how this paradoxical process works,

Constantly scratching and picking at an itchy rash really does make it worse. But why? According to newly released research using mice as a model, scratching aggravates inflammation and swelling in a type of eczema called allergic contact dermatitis.