Hi iLLER T, apparently a crystal called Conichalcite is helpful for treating psoriasis and if you would like to know more information about that particular crystal, here is a link that will take you to some:

http://www.hehishelo.co.uk/stones/Conichalcite.htm

Also, the following site claims that a miracle cure for psoriasis has been discovered utilising banana peels...I suggest caution whilst reading what is there but since the site gives the information freely, it seems kosher. Here is the link:

http://www.awwwsome.com/theothernews/cure.htm

I hope this helps,

Kundalini.