itchy palms and knuckles on hands

I have been to a Dermatologist and diagnosed with Psoriasis.
I dont understand how this could be Psoriasis.  It first appeared as a rash on my neck and spread to my hands and elbows.  During the episode what I thought was a razer burn developed into staph infection.  I took the penicillon for 10 days, I forget the name of the medicine but it helped and while my leg isn't completely heeled (distant scars that itch and bump)
My palms are red, itchy and painful. My thumb knuckle had a round red rash that severely itches and is painful.
If I scratch the skin appears dead, white and peels off.  
My thumbs are red and swollen.  
This has been going on since October 2008. I've never had skin issues, I've always had very healthy skin.  
I think I caught something at the Beauty Salon because it wasn't until after that I had the issues.
I don't know if its totally unrelated but I've had charley horses in my legs that wake me up at night and the strangest thing the other day, my neck had what seemed to be the beginning of a charley horse, if thats possible.  The muscles got tight but went away quickly.

[jagesh50]

A chronic lichenified eczema may resemble psoriasis, but itch more than does psoriasis.