I too, pick my skin constantly, I didn't know there was an actual name for it, but I have scars everywhere, on my forearms, upper arms, legs, stomach, face..if I see something to pick, it will be picked. I also bite my nails and the skin around my nails until they bleed, sometimes I even peel the top layer of my nails, gross I know. lol.

Someone had mentioned zoning out while doing this, I do, I go into deep states of zoning out and I either pick for hours, bite my nails for an hour or start tapping, cracking my knuckles, or keeping a repetitive motion of my leg or foot somehow, always.