Does anyone poke themselves with pencils or pen?

I'm not quite sure how I developed this sensation of poking myself but I just have the urge to poke it on my hand/wrist area. Is it just me or does other people have this weird but soothing feeling? Because when I poke myself with a pencil or pen, I would feel a cold tingle that I sorta indulge on haha. It's like an addiction; just like cigarettes except I'm not sure if its hazardous in anyway to your health. LOL.. I did stop the poking but it sorta sneaked up on me from time to time so I'm just wondering if this is something I need to be concern about.