You could try moisturizing more and see if that helps. I have a lot of pain on my scalp but no obvious psoriasis there. The pain is worse in the winter when the air is dry. I think it must be some kind of inflammation. the best test would be to moisturize part of your body and see if the itching goes away.

I grind oatmeal into powder and put it in a warm (not hot) bath, soaking, and bathing, then I rinse off in the shower, and I use a product that is like a hair conditioner, only for your skin. You smear it all over, then rinse off. That stops my itching. I hope someone else can find relief with this cheap remedy. I find that steel cut oatmeal works better than instant oatmeal, and is usually cheaper. You can buy it in bulk at some natural food stores. You can get the rinse off skin conditioner anywhere that sells body wash and shampoo.

She gave me an antihistamine which helps a little

You should ask your doctor. You could try an allergy medication for it. Hope you get some relief soon.

Same with me, no rash, just the arthritis!