What Could Cause Sharp, Needle-like Head Pains Triggered By Touch Or Itching, Lasting Up To 30 Minutes?

I always have really sharp needle prick pains that seem to move around my head. It sometimes starts as an itch that if I scratch sets off a series of 1 or 2 second sharp excruciating pains in 2 to 20 second intervals,and can last for up to 20 to 30 scary minutes with me finding a position to try and hold and trying to will away the pain