Rash on Head in and above ears and between breasts, they itch and then flake

I started with a tiny rash on back of my head 5 years ago now it's grown to half of the back of my head above and inside my ears and now between my breasts the itching is not quite all the time but I find I am scratching a couple times a day and it hurts , it looks red most of the time then every couple of weeks it go's slightly brown then go's flaky. The rash in and around my ears and on my head tend to bleed after I scratched them a lot. I wash my hear with natural organic shampoo and conditioner and i dry my ears out after a shower which has made the itch bearable but its not healing . So far the any creams prescribed haven't worked. As the doctors thought is was ex-ma. Can you help.