According to a report by the Associated Press, experts say scratching an insect bite or an allergic itch may feel satisfying for a short time, but it triggers a chain reaction that intensifies inflammation and prolongs discomfort.

Dr. Daniel Kaplan, a dermatologist at the University of Pittsburgh, said research has shown that repeated scratching activates immune cells that promote inflammation, making the affected area redder, itchier, and slower to recover.

"If you leave a mosquito bite alone, the itching may disappear within minutes," Kaplan explained. "But if you keep scratching it, the irritation can last for up to a week."

To understand the process, Kaplan and his research team conducted experiments on mice. They applied an allergy-inducing substance to the animals  ears and prevented some of them from scratching by fitting them with protective collars.

The mice that were unable to scratch developed significantly less swelling and inflammation than those that repeatedly scratched the affected area.

Researchers found that scratching stimulates nerve cells to release chemicals that activate mast cells—immune cells that play a key role in allergic reactions. This creates a cycle in which inflammation causes more itching, leading to even more scratching.

Scientists believe scratching may once have offered an evolutionary advantage by helping remove insects or parasites from the skin. The study also suggested it could provide limited protection against certain bacteria. However, researchers say these potential benefits do not outweigh the damage caused by excessive scratching.

Kaplan emphasized that scratching remains harmful overall and should be avoided, although he acknowledged that resisting the urge can be difficult.

Doctors recommend treating insect bites with over-the-counter anti-itch creams, calamine lotion, or cooling products. Kaplan also suggested creams containing menthol, which create a cooling sensation that helps reduce the urge to scratch and break the itch-scratch cycle.