It's tough to resist scratching an itch — and evolution may be to blame

[Chip (OP)]

https://www.livescience.com/health/its-tough-to-resist-scratching-an-itch-and-evolution-may-be-to-blame?utm_medium=referral&utm_source=pushly&utm_campaign=All%20Push%20Subscribers

In mice, scratching activates an immune response that helps to protect the skin against harmful infections, which could also explain why humans find a good scratch satisfying.

When mice scratched itchy patches on their ears, the tissue swelled, and pain-sensing neurons released a molecule that attracts immune cells called neutrophils. Mice prevented from scratching with a ‘cone of shame’ had less swollen ears with fewer immune cells in them.

Those that scratched were also less likely to have the potentially dangerous bacterium Staphylococcus aureus on their ears, which suggests that scratching has anti-bacterial benefits.