Well, here's one that worked for me years ago when nothing else helped - and I had been to dermatologists, tried creams, etc. Mind you this was the seventies so they probably have lots more options available now. I was living in France and an elderly Arab man at a cafe I frequented noticed fairly severe psoriasis on my hands. Next day he brought me in a small box of natural henna. He told me to make a paste of it with water and a few drops of alcohol, put it on the patch of psoriasis and wrap it up in a bandage overnight. He said that in Morrocco people use henna all the time for skin irritations. I was sceptical but I tried it and it worked, pretty quickly, I might add, when all else had failed. It is kind of messy - this was the colored henna but they do make a colorless variety that you could try. This falls into the category of won't hurt anything - might help! Good luck!