Have used cortisone cream and Benadryl. Doesn't seem to stop the itching.
Organic grass-fed beef or bison whipped tallow. Sometimes called face & body tallow butter. Rather under the skin or above, it's the only product that helps the itch, soften & help heals the psoriasis patches faster as well as lighten them. I apply as needed. Find it on Esty. I hope this helps.