Well, I saw the pic on the tool bar, so here I am. My best guess was impentigo.....indian fire. Well, the good thing, is most of the advice wouldn't have harmed it and you acted and are heading in the right direction.
For whatever it is worth, I like salt water to help cure any bo-bos. If the child can just bathe in a tub, with epsom salts and then do whatever kind of treatment with healing properties, you are on the right track. But make sure you cut nails and clean real good under them. Also, clean the nostrils of the child, make sure you give cold med, rather medical or natural, if symptoms are present, because I suspect the problem went from nose, to nail to wound.
If there is any chance at all I am right, have a talk about spreading infections and washing hands. You might want some kind of antibiotic ointment put in nostrils too.
