Haircuts itch, why?

Ok, I got a trim today at this coffee shop. Right, why would you get a haircut at a coffee shop? But this lady new one of the guys on set that overheard us needing haircuts, so he called her up and we got some trims sitting in the humidity of Tulsa, Oklahoma. On the drive back to the hotel, and even right now after the showering off of the excessed and removed hair, I'm still kind of itchy. What's the deal with that? It doesn't itch on top of my head. But as soon as you take it off, wow, does it itch. That's my curiosity for the day. Peace.