For real though, my husband has eczema mostly concentrated on his hands and they get real torn up in the winter especially. If it gets really bad, we’ll get him a pack of latex gloves, he slathers on Vaseline and then I help him get the gloves on, and then he sleeps that way. It’s the only thing that manages to make a significant difference. It’s not comfy but sometimes his fingers bleed so we gotta do something.
In the netherlands doctors use Cetomacrogol 1000 (with 10-30% vaseline) or a variant or Bag Balm (less usesd) for people having eczema or psoriasis. It adds disinfectant and hydration properties. Works fantastic
Vaseline is just a barrier that keeps moisture from escaping, it's called an occlusive.
I would suggest using virgin coconut oil, shea butter or cocoa butter and having him wear Nitrile or vinyl gloves, latex will break down. Those 3 oils are an occlusive that have natural moisturizing and healing properties. Think of it as lip balm for your body.
I used to do this too, until I found something more targeted. I also have a sensitivity to common lotion ingredients so can’t use them without making things worse. Unfortunately the petroleum jelly is never absorbed so without the gloves everything you touch gets greasy