I have tingling areas on my back....what is it?

this is going to sound crazy and I can't find anything online regarding this. I started using Nicotine gum to kick chewing tobacco. I was chewing quite a lot of gum everyday. I used to carry alot of stress in my last job, so the gum took the edge off of everything including the addiction.

But I started to experience a tingling sensation on my back. All I can say is that its not inside my back but on the surface, several different areas tingling and itching at the same time. It usually came on when I got really stressed but over time it started coming on randomly.

I finally got off the nicotine gum and the feeling went away. Now I am in a new job and the feeling is coming back again, not as bad as when I was taking the gum, but it happens at random times of the day and not necessarily when I'm at work. I try to remember the things I'm thinking about when the sensation comes on but it ususally is random things and not related to work or stress.

It's the most bizzare thing I'm feeling. It's the equivalent of nails scratching a chalkboard or an itch you can't scratch. It's on my back though, nothing is visible like a rash or anything, but it feels like a spiderweb of tingling on my back. I can't shake it.