Help with boyfriend flaky scalp?

[agoddess2die4]

My boyfriend doesn't have long hair, but you guys know so much about hair I decided to ask for help. His hair is usually only and inch or two long, but he has some of the flakiest scalp I have ever seen! He even sometimes gets little patches of skin that come off. Right now he is using the Aussie Moist 2-in-1 shampoo/conditioner, but he's tried other stuff and it doesn't seem to help. I know he has sensitive skin, he can't use any cleanser on his face and usually uses water only for it, but that's not an option for his hair (to him at least) because it gets greasy easily and is very noticeable with such short hair. Are there any recommended shampoos or treatments you guys could suggest to tame his scalp? He hates it and finds it embarrassing.

ETA: he has fine, thin hair if that makes a difference.