No direct experience but my sisters 3rd DS suffered terribly with eczema on his face which got worse once he started teething . like your DD cortisone only worked temporarily. her GP ended up taking swabs as it was so bad it was oozing stuff and it turns out he had a staph infection which is why the cortisone only worked temporily. he had to go on ab's to clear up the infection first then they were able to tackle the actual eczema.