What is an itch?

Or more specifically, what causes an itch?.

I’m not talking about an allergic reaction to an insect bite or nettle sting, what I really mean is a sensory itch.

The kind that just arrives and you just gotta scratch it.

While on the subject, why does scratching alleviate it?

http://www.straightdope.com/classics/a1_090.html

“An itch,” one of my doctors once told me, “Is a low-grade pain.”
It’s an irritation caused by something firing off one of your pain sensors, and it’s telling you to do something about it. The easiest thing to do is to scratch, which works if the source is something small that can be dislodged – an insect or a little piece of something stuck in your skin.

http://www.madsci.org/posts/archives/mar97/857507616.Me.r.html

:smack: :smack:

In future use the search function you stupid twat