Itch-scratching is a paradox. It can be both bad and good for you, a new scientific study suggests.
According to the University of Pittsburgh scientists, poison ivy and other allergens trigger mast cells in your body that release chemicals that can result in itching and inflammation. Scratching the itch makes it worse.
"The act of scratching is actually triggering the inflammation by synergizing with mast cells to make them more effective," says dermatologist/immunologist Daniel Kaplan. For example, consider a mosquito bite.
"Most of the time, it'll go away in five, 10 minutes," Kaplan says. "But if you start scratching it, now, you get a really big, inflamed, itchy lesion on your skin that can stick around for several days. It's a lot worse. And I think this could be a mechanism that explains why."
From Science News:
Now onto the good news: Scratching lessened the amount of potentially harmful bacteria (Staphylococcus aureus) on mice's skin, perhaps through the heightened immune reaction it prompts.
"That was a clear demonstration that scratching can have a benefit in the context of an acute infection," Kaplan says. But too much scratching can rip the skin and usher in more bacteria, he cautions. "In that sense, scratching, through a different mechanism, also makes things even worse."
Eventually, he adds, this line of research into the chemical mechanisms of itching could lead to new treatments for itching disorders.
Previously:
• See this horse bend its head upside down to scratch an itch, making a funny and unexpected face in the process
• Powerful hallucinogen could bring relief to chronic itching
• Song based on the woman who scratched an itch until she reached her brain
