My whole life i have had a severe invisible itch under a single point of 1 fingernail. i spend hours a day ripping the nail off trying to get at it, causing extreme chronic pain. what could this be?

See your doctor: Symptoms like these are best deterimed by a thorough evaluation by your physician. Based on his/her findings, a treatment plan can be developed to help you.

Well: I'm sure you have had it examined; a dermatologist would be the best to evaluate; lets say thats done, no evidence of tissue damage. It has turined into a feedback loop and could be causing or related to anxiety and problematic behvior. An snri medication, like Cymbalta (duloxetine) 30mg, may affect ascending nerve conduction and the anxiety behind the behavior, the feedback loop less w/time, better control.