What Causes Dry Scaley Skin Behind Ears?

I have dry scaley skin behind my ears, when I scratch it, notice yellow flakes/residue. Since scratching I noticed 4 pinpoint sized dots in that location. Also, there is a sore of some kind in the fold/crease of my upper ear that keeps leaking yellow fluid and crusting over. And.....there are 4 larger size irritating red sores on my back that either have dried blood scabs, yellow scabs, or white scabs. (Was size of nickel, very red, and crusting, now shrinking with much less discharge). Been treating all skin irritations with Neosporin and moisturizing with cocoa butter for about 10 days. (Similar rashes/spots in the past. Years ago, doc gave me an RX for a foam to treat rash at the nape of my neck/hairline area.) Have other medical issues....one being Thrombocypenia. Not sure if I need to revisit Hematologist (been 10 yrs) or Dermatologist.....and the relationship if any between the oozing red sores on my back and in my ear, and the flakey "rash" behind my ear and previous scalp rash and sores. I did go to my Internist yesterday.....,she was in a hurry, but referred me to Dermatologist. She is checking my platelet and WBC count at my request. Do you have any advice to share?