Severe full body psoriasis flare up. : (

It's been about 7-8 months since my mothers full body psoriasis got worse. Currently it's covering 75-80% of her body especially in the torso and upper thighs. The patches are red, shiny in some parts and very thick and scaly in some. Overall there is a lot of shedding, dryness and burning and pain plus itching. She has started feeling chills and slightly feverish in evenings as well since the last few days. Can someone please help as to what to do to alleviate these conditions. I know it cannot be cured but if I could get some pointers for the following: -do and don't in food. -do and don't in general -tips to manage and soothe these symptoms. I was reading online that these symptoms are pretty severe and can be considered fatal sometimes. Please help me take the next step :(