Can you get skin cancer/ink poisoning from drawing on yourself with crayola markers?

My teachers always get on to me about how it can give you skin cancer and whatnot. I tend to draw on my left arm a LOT. And by a lot, I mean completely covered from the wrist to my elbow in marker patterns (Today it was an American flag xD). I do this almost everyday (I take a few days off, just incase this ink poisoning is true :P) Anyways, I was wondering how much damage this could cause? So far, I have seen nothing out of the ordinary. Not filling ill, etc.