I have had P. since i was 6 years old (i am now 33) and nothing seems to work.
If you haven't already, check out the posts about psoriasis diets. There are some books that are recommended in other posts and this website also has a booklet or information related to diets. For me a healthy diet full of green leafy veges and vegetable juices, really has changed my psoriasis around. Try eliminating junk food and the stuff you know which is not good for you (coffee, alcohol, fried foods etc) for a few months and see what happens. Also organic veges are supposed to be better.
People have eliminated psoriasis or have it well under control by doing this, however they are very dedicated to the diet. Don't worry people have said they can eat small amounts of the bad tasty food but only after clearing their skin.
The sun and surf works wonders, also there are some light treatments which also work. Give it a go what do you have to lose?
If you try this, keep us posted.
Regards,
Nat