i would think its is a form of si. Has your psychiatrist never asked you if you have self injured or not? Every assessment i've had they have all asked me and they ask how and where and how often etc. If he hasn't asked then maybe you could bring it up by sayin to him that you have a compulsion to scratch yourself in various places when you are under stress or upset etc and ask him for his advice on how to stop. This may lead him to ask questions which you should answer truthfully. If he doesn't ask any questions then he's not very good in my opinion. I hope this has helped. Sorry if it hasn't. Good luck and take care of yourself. Feel free to pm of anytime if you need. Keep us posted