Please explain how do steroid creams help psoriasis?

See below. Steroids are anti-inflammatory. Psoriasis is a type of inflammatory condition of the skin. Steroids suppress the inflammation and thereby reduce the redness and scaling which characterize psoriasis.
Psoriasis. Steroids are anti-inflammatory medications. They decrease the autoimmune and reactive cells in the psoriatic patches to allow normal cells to squeeze in and reconstitute with a more normal skin cell.