Feel one's skin crawl

To feel one's (neck) skin crawl...

...what does this phrase mean and where does it derive from?

I'm on uncertain ground here, but in situations of fear or genuine horror, the autonomic nervous system kicks in and causes, among much else, effects on the skin. For one thing, the blood supply to the interior of the body is increased and to the exterior (like skin) is decreased. So the skin may feel colder. Another effect is piloerection, or gooseflesh. I believe the latter is what is mostly meant when one feels one's skin crawl, or one's flesh creep. Sometimes one shivers a bit as well. Of course, these verbal expressions are often used figuratively. You may say of a horror movie that it made your skin crawl, when it actually didn't. Or you may say of the latest budget proposal in the U.S. Congress that is makes your flesh creep. SS