Ya know, I used to think that I picked out of a compulsion. It really, really felt that way to me. It did not feel like a symptom of anxiety. And, I do think that for me there is an element of compulsion to it. However....going on anti-anxiety meds and working on getting my anxiety under control did lessen the urges to pick. It's not 100%. Sometimes I do still feel that compulsion that I must pick, but I'm more aware of it, thanks to the work I've done with my therapist, and I'm able to notice the urge without acting on it.

It really may be a pure compulsive act for you...but it could also be due to underlying anxiety. Just because you aren't having constant panic attacks or have no trauma in your history, doesn't mean that you're not dealing with some level of anxiety. I hid my anxiety so well that no one noticed and I even managed to fool myself for a very long time.