I have a "patch" of psoriasis on the back of my head. I can go for hours not itching, and then will have intense episodes of itching. I have some Rx med which I use at the worst times. I've been using Lissima for about three weeks, every other day when washing my hair. For the day of the use, I do see some diminishing of the itch, but by the end of the second day, I see increase. I'll keep using Lissima as I do think it helps.