My son has a couple spots that sound similar to what you have explained, not quite as bad but similar. A dr once told me that he has a form of psoriasis. I started having him use a shampoo from a natural line called Jason.the shampoo he uses is the biotin one. It keeps it practically gone. I can tell when he has used a different shampoo, because it comes back with a vengence .  

Also, I have read that essential fatty acids are awesome for skin problems. These are found in foods like fish. You can get capsules if he can swallow them. They come as flax seed oil, fish oil, and sometimes combo of different oils. Cod liver oil is excellent and is alot smaller that others. 

Anyhow, I hope you are still around, and this has helped somewhat.