That sounds a lot like what I have. At one point after I was pregnant, I had Psoriasis, mainly on my scalp. Went to the doc's, gave me some meds, tried some, it never really went away. Over time I was just trying to deal with it, using Tgel, head and Shoulders, etc, nothing really working. I looked stuff up online to find natural remedies, this is what I found and will work for whatever it is that you have; you take a squirt or spray bottle and put 1 parts Apple cider Vinegar to four parts water. I eventually found out that I had Sebhoreac Dermatitus sp?. If you put this Apple Cider Vinegar mixture on your scalp after you shower/wash your hair, it helps to nutralize the ph balance of your skin. It made the itching stop almost right away and the flaking/sore's go away soon after.
However, I did also have a dermatologist appointment set up prior to finding this natural remedy. When I went she did prescribe me some meds, but I don't like to take meds forever so I will take a break from them once in a while and go the Apple Cider Vinegar route. Hope this helps.