I do the same thing, and have for years and years. The general rule of thumb is that if it bothers you to the point where you find it interfering with your general happiness/life/well-being, you should get treatment for it. You never really know what something like that is prompted by until you explore it, as others have said.

I've tried a bunch of things to stop, but nothing has worked for me so far. That said, I haven't really maintained the "stick to it" attitude, either. Some things that were suggsted to me are:

-A nail polish that tastes awful...it's made to break habits like this, and is therefore non-toxic, just really bitter. I can't remember the name of it, but Google would help.

-Wear gloves when it's not too hot, especially when doing things where I wouldn't notice the chewing (ie: reading, using internet, watching tv/movies, etc.)

-Practice mindfulness, to be aware of what I'm doing at all times/what's going on.

I think that if you really want to stop, you can. I dunno whether it falls into OCD, OCD tendancies, or just a habit/addiction that self-soothes, but it's definitely a bit bothersome. I haven't been diagnosed with OCD, but I definitely have some compulsive tendancies, so it's probably somewhere on the spectrum.