What the dickens?

My hubby asked me the other day, "What does it mean when one says, 'Hurts like the dickens?' What does 'dickens' mean?" Um.... I don't know and I'm afraid to examine it too closely to figure it out. The only thing that popped into my head was Charles Dickens. But... why would one refer to his last name as a meaning of some sort of pain? Was he a painful person? Or was it that his writings painful? In either case, it seems... stupid. Any thoughts?