I read in a Ukrainian magazine about psoriasis and how to treat it, all you have to do is to buy natural coal tar, and put that tar on your psoriasis for 5 hours after that wash your head with coal tar shampoo, do this for 3 days after that you should take a break for a day, and repeat the same process after the break, it really helped me and now my scalp is 85% cured, i still need to cure it a little bit :)
I think that this information will help some of you!
Best regards, Radu.
P.S. sorry for my bad English.