You poor thing!

I second the humidifier, we have one for ds and it works a treat. We also found that warmth and heat caused it to flare up so try and keep him as cool as possible and have a little fan in his room at night too. We have also tried a myriad of creams, the one thing that works for him is a dermeeze moisturiser that is clear and sticky like an ointment and seems to plump up his poor skin.

I hope you find something soon that helps and gives you both some relief.