C.J.
Methicillin-resistant Staphylococcus aureus - It lives on our skin in various areas including nose. It flares up or "colonizes" for various reasons. I had a cut in my nose and had a huge flare up about two years ago. While it is resistant to some antiB it is not to all. In fact, the amount of antiB you take can play a role in how the medicine they give you reacts with the bacteria (per the doctor that treated me).
It is not flesh eating, but can cause cellulitis (the separating of skin from underlying tissue). This is typically remedied when the infection clears (as was my case).
My nephew had this in his knee when he was just a little guy (2 or 3) he had to have a cast and a walking IV. It was very scary for my SIL and Brother.
We supported them by listening, praying, not trying to diagnose or be experts and encouraging them that they were doing everything right by listening to the doctor:) That is what I'd do with your friend , too.