I am a picker. Not exactly like what you are describing, but if I see a bump, or a scab, or a hair not where it should be I HAVE to pick at it and would love it if my husband or kids would let me pick at them too, but they don't. :P Anyway, you aren't alone. When I'm stuck somewhere and I can't get away and am agitated I wring my hands, chew my fingernails, write lists, or even rip napkins into little bits.