E.D.
I second the suggestion to call a nurses line.
*My* understanding is that a person can often treat impetigo at home, using topical antibacterial cream, and keeping wounds clean and covered. However, if it does spread, or is a more serious infection, a oral antibiotic becomes necessarily. When my daughter had impetigo (staph or strep infection), she was prescribed an oral antibiotic. Also, I disinfected the entire house, especially the bathroom (which I disinfected after each shower). I kept her wounds very clean, put triple antibiotic cream on them, and covered each with a bandaid.