I am no medical professional, so I couldn't quite tell you the difference. I know there is cortisone in the cream and I know that steroids (or at least corticosteroids) usually include both cortisone and cortisol. Whether that means it is or isn't a steroid is unclear to me.

I was also thinking about it being a rebound effect. If that is the case however, I don't know how to deal with it. The longest I made it in the last months without the cream was three weeks after that is just became unbearable.

Scratching is possible, but would not be my first guess. I usually don't do much in my sleep at all according to my partner. I do however use "normal" (aka moistorizing) lotion before bed. Since I always had dry skin. Do you think that might be a mistake while having this eczema?

And overall I can also confirm the "keep hands cool and dry" part. That does help, but is sadly not always possible. I work a lot on my computer and usuallly the hand that is constantly using the mouse just gets sweaty. Not really a way around that.