I think there is a line on CurlMart call Max Alchemist. Its claims to be a dandruff shampoo without sulfate.
I have searched YEARS for a shampoo that will take the S. Dermatitis away. And I have found it in Dermarest. Its usually right beside the Nuetrogena. That stuff work GREAT for me.
I LOVE it because it has a conditioner in it too, so it doesn't strip my hair of moisture like other products do.
If you can I would try that. I have even mixed the Dermarest and a tar shampoo (like Nuetragena).
I think that might be a good try for you. You might be experiencing that the Nuetragena is too drying for your scalp and the Dermarest + Nuetrgena might give you the added moisture that you need!
Hope that helps!