Another update - rash never went away, but with a few ups and downs became more manageable.
She was tested for fungi and they found nothing, and docs simply weren't interested enough to keep digging. Its possible she has had more than one type of rash.
But she has been taking steroid creams, particularly when it gets bad. And the doc prescribed a stringer one which works better.
Got a COVID vaccine yesterday and it came back with a vengeance.
Not on topic, but she also had a very achey body last night, leg and shoulder particularly. She gets aches and pains every now and then, but this was more intense than usual and more widespread, so was likely vaccine related to vaccine.