Raw bum not improving! Any tips?

Ellie

My daughter has had a nappy rash almost a week now and there is a little patch that's raw and weepy and won't scab over. The rash itself is pretty much gone but not the patch.

I've tried giving her nappy free time and using sudocrem, caldesene powder, canesten cream, egg whites, diluted apple cider vinegar, baking soda, coconut oil. Nothing is improving it.

Any ideas?