I can't remember if the person I am about to talk about had psoriasis or eczema. I know both look kind of similar but are in fact very different conditions.
Anyway, after trying numerous creams, potions, jollops and dietary restraints, he had a nice holiday on a resort on the Red Sea.
The salts in the ocean there combined with ultra high compounded sun rays treated his skin very kindly.
There are sun creams available that block out the harmful rays but let in the safe UV ones, so skin cancer was not an issue.
May be worth reading up on.
His condition came back, I think it can never fully disappear, but it is certainly better than it ever was.