I have Erythrodermic Psoriasis. Any home remedy 2 help with itch/pain? Prescriptions haven't helped.

Colloidal oatmeal baths, try taking a non-drowsy inducing antihistamine orally, aloe vera gel(If doctor says that it's OK to try), Benadryl ointment, and I'd even try some of the miquito bite topicals (again if the doctor agrees it's OK).

My husband suffered from this and I can completely understand the pain and itching.  We tried many things but ultimately, a combination of epsom salt baths and acupuncture and herbs have relieved and nearly restored his skin to good condition. He tried the drugs and nothing worked. Here's some things that helped pretty immediately. 

Epsom Salt baths - 3-4 a week to start.  2 pounds of epsom salt in hot bath water, the hottest you can tolerate.  Stay in the bath until water cools.  The baths were amazing to control the itching at its worst.  But you will need to combine with benadryl until the worst is over.

Unrefned shea butter or extra virgin olive oil after the bath- Now that his skin is controlled, the Unrefined shea butter (you will have to order from the net) has greatly reduced the inflammation. 

We tried Bromelin/Tumeric supplements on an empty stomach to deal with the pain as it is a natural anti-inflammatory.  Watch your diet carefully as a good anti-inflammatory diet will help bring relief.

As a side note, my husband's episode was triggered by going off Humira - because the humira provoked a severe infection.  We opted for a homeopathic path as the drugs recommended had too many side effects.  Good luck and I hope this helps.