Ever wonder why sunburns hurt so much?

By Casey Frye, CCNN Writer

Have you ever forgotten to put on sunscreen while you were playing at the park or swimming in a pool? Sometimes, the sunlight tans your skin. No harm done. Other times, though, your skin is throbbing and it hurts to touch any part of your body! I’ve always wondered why the Sun did this and thanks to a team of researchers from Duke, Rockefeller University, and University of California in San Francisco, I finally have an answer.

Someone pass the sunscreen, I’m burning up!

You see, the research team knew that a molecule called TRPV4 is responsible for causing pain in many parts of the body and they wondered if it could be the culprit behind the sunburn pain. To put the idea to the test, the researchers used two types of mice. Some of the mice were absolutely normal, while others had the TRPV4 molecule missing from their skin. After they exposed the mice to sunlight, the normal mice were sunburned badly, but the mice missing TRPV4 were absolutely okay!

There’s an explanation for this. Normally, TRPV4 acts like a door that lets calcium in and out of cells. The researchers found when the skin is exposed to the sunlight, TRPV4 ‘opens’ and lets tons of calcium into skin cells. Well, more calcium has to be good, right? How could it not be, it’s important for strong bones and healthy muscles! That is true, but not in this case. When calcium went into the skin cells, they also brought a molecule called endothelin with them, which is known to cause itching and pain!

Now that the scientists had identified the cause of the discomfort, they could go about putting together an awesome cure to relieve it. That’s where another molecule known as GSK205 comes into play. I know, lots of molecules to keep track of. Bear with me. This GSK205 guy is great for ‘closing’ TRPV4, which means that the itching and pain would be less! So, researchers took some of the GSK205 and mixed it with rubbing alcohol before lotioning up those poor sunburnt mice. Guess what happened? The animals barely felt pain anymore! This discovery could lead to a whole new strand of products to soothe those painful sunburns.