This has been on off for a couple of years. His scalp looks painful with angry red patches (also gets these on his body) and then the dandruff is large, yellowy, oily- looking flakes. He refuses to discuss it and I think he is washing his hair with water (he used to wash it most days but is now down to every third day and it does look greasy by the end of the second day) and then occasionally with my shampoo. He won't try medicated or targeted shampoos. His hair is black and so the flakes are very noticeable. I want to help him as I can see it's painful but he refuses to discuss it.