If scratching is bad, why does it feel so good?

Factual Questions
1

Many times in my youth I was told not to scratch thinkgs like rashes or bug bites.

But it feels so good to scratch!
Why hasn’t evolution made scratching something that you shouldn’t feel bad?

Of course this is all predicated on the medical advise of my mother and since I’m not blind, that is not 100% reliable.

2

Rubbing your eyes feels sooooo good, too, but that’s supposed to be bad for ya . . . any little bit of foreign matter can scratch your eye, I guess. Sigh.

Two opposite WAGs on scratching:

1)There are some instances where scratching is beneficial (removes irritating chemicals from the skin, or small parasites under the skin, perhaps) but most skin irritations of modern man are not helped by it.

  1. The desire to scratch is utterly extraneous. Itching is just a low-level firing of nerve endings, and scratching overloads the nerve endings, providing temprorary relief (that’s not a WAG, that’s actually true), but evolution never really “meant” us to scratch where it itches (that’s a WAG.)
3

With rashes such as poison ivy-you spread it, because the oil from the blisters gets on your fingers and as you touch yourself (shut up, you pervs!), it gets on the rest of your skin.

With chicken pox, probably you can scratch one open, and they bleed and get infected. Not to mention it can leave scars.

Bug bites-I’ll scratch until they bleed and then put a histamine blocker lotion on. It has this wonderful painful sting that sucks all the itch away!

4

You scratch to create pain.
The pain is easier to take than the itch.