Hi oyster,
I happened to be visiting and posting on another thread here and saw this...and thought I would mention that psoriasis has been associated with gluten sensitivity and/or celiac disease~ some improving on a gluten free diet. Celiac disease can often be 'silent' except for some of these seemingly unrelated problems, although if you have any GI symptoms..all the more reason to be tested. Gluten sensitivity can cause wide ranging neurologic problems as well.
You might want to talk to your doctor about running a celiac panel, being sure they include the
antigliadin antibodies.
Food for thought~
Cara