Has anyone had good results with paleo helping to reduce psoriasis?

 I have a friend who has it, she is on paleo except she still eats some
butter and gets some traces of dairy from the butter.

 I have tried to get her off all dairy but she's a stubborn friend! Anyway,
could casein, even tiny traces,  be causing this, does anyone know about
psoriasis?

Thank you,

Mary