I know that there are lots of common type rashes that kids get... but how do I tell the "serious" from the "not so serious" and the "don't need to worry"

DD has a rash/marking on her face around her mouth and under her right eye. It is not blistery (but was and peeled), is not scabbed over, does not cause her any irritation and she has no fever.

I have consulted a GP (not our regular one as she wasn't available) and he said nothing to worry about.

I asked about hand, foot & mouth, roseola, and heat rash. It is none of those. He asked me to go back if the rash causes her any discomfort or she develops a fever.

Does anyone else have any suggestions?