The researchers also demonstrated that scratching prompts pain-sensing neurons to release a chemical known as substance P, which triggers mast cells: cells involved in the immune system, causing inflammation and itchiness via neutrophils.

Scratching where it itches reduces the presence of potentially harmful bacteria on the skin, studies in mice show.

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.

Mice that were free to scratch their itchy ears saw the number of immune cells go up and levels of infection-causing bacteria decline

Scratching is something most of us do mindlessly. It doesn’t have to be a big deal, unless it is in hard to reach place. But it can also become a nuisance when you keep itching and end up hurting yourself,