@fBoyle-- I have used 1% hydrocortisone cream in the past. It's not something that I use regularly, because there are dangers to regular, long-term use. But when my psoriasis is at its worst with constant debilitating itching, hydrocortisone cream works well.
Other times though, for mild itching, I prefer more natural options like aloe vera gel. Aloe vera gel is very soothing but make sure to get pure aloe vera gel. Some lotions contain aloe vera gel but those don't work too well for the itching.