Why it’s important to scratch that itch!

By Alejandro Freixes, CCNN Head Writer

girl scratching

Scritchety-scratch. Itchy skin makes you want to scratch!

What causes an itch, though?  I mean, sometimes it could be a bug crawling on your arm or a rash, but what about when there’s no obvious sign of itching?

Scientists used to think that itching was really just when your nerves felt pain or temperature, but now they’ve found there might be a highway from your skin to your brain just for itching.

It turns out that the molecule – the tiny little pieces we’re made of – that causes itching likes to hang out in our heart. The fancy name for this molecule, which helps control blood pressure too, is natriuretic polypeptide B (Nppb).
Now, scientists didn’t always think Nppb was responsible for itching. So, when researchers at the National Institute of Dental and Craniofacial Research found this thing paying a visit to nerve cells, they started scratching their heads – ok, maybe not literally, but you know what I mean.

So what did they do? They tested mice. I know, not a terribly surprising thing for scientists to do. But anyways, they found things that normally made a mouse start scratching like crazy had zero effect on mice with no Nppb. Aha! Then, if they injected the non-itching mice with Nppb, suddenly the little guys started itching and scratching. Bingo.

Now, before we go shouting down the streets that Nppb is the evil itch master, it’s important to note that this research hasn’t been tried yet on humans. However, researchers are very confident that the molecule Nppb is at least a solid clue in finding that mysterious itching highway inside us.