Why does my scalp itch when I watch scary movies?

[Lightnin']

Weird, I know.

I shave my head, have for years now. Lately I've noticed that whenever I'm watching a particularly intense scene in a horror movie, the top of my head starts itching really badly. As soon as the scene ends, it stops- but I always end up leaving the theater with a red scalp, because I was scratching at it constantly.

Does this happen to anyone else?

[Philster]

Local goose bump reaction. WAG. Sue me for a WAG in GQ.