I too have had a surprising skin change on HRT, i've suffered eczema for my entire life, i've been in hospital many times & I was put on immno suppressants early last year.
I couldn't be out in direct sunlight for fear of my skin coming out in a heat rash thus opening the door for a severe flare up. Over the last year my skin has improved in leaps & bounds, I can now be out in sunlight for a couple of hours without the heat rash starting up, i've not had to take the immno suppressants for several months now & my skin has never been clearer. I knew that HRT could have a difference with regards to my eczema, there was an equal risk of my skin improving or getting worse, I got lucky with this roll of the dice.
My skin can still react badly to make-up so I rarely risk using it but at no other point in my life has my skin been so clear for so long.