Hi: I also have Psoriasis and I have tried all you can imagine, from topicals, to pills, baths, soaps, acupuncture, autohemotherapy, You named it I have tried it all. Last year I started a detoxification process and My P was WILD!!! I was covered from head to toe, It was itchy, PAINFUL and really embarrassing.
I kept going with the detox and changed my diet, No dairy, no flour, no sugar, no gluten. I also started probiotics and I started a homeopathic treatment, a year later I am about 85% Psoriasis free. It has been a very slow and painful process and I always itch even when I have no patches on my upper body just a few on my legs.
I tried every cream and ointment, every oil to calm the itch. The only thing I have found useful for me is Cocoa butter. This product has been the only one I've found calms my skin immediately. I use it all over my skin from face to toe and it is wonderful!