Our dd9 had impetigo around her mouth about 10 times last year! They say she has staphylococ A in her nose and since we put bactroban (an AB) IN her nose, she is symptom free (eh...I mean: no impetigo any more). If she forgets it 1 day, it'll be back in a sec.
So for us the deal is: stop the staphylococ!