The key to treating -- and preventing -- impetigo is to practice good personal hygiene and maintain a clean environment. Once the infection occurs, prompt attention will keep it under control and prevent it from spreading.
Even if only one family member has impetigo, everyone in the household should follow the same sanitary regimen. Wash regularly with soap and water. This should help clear up mild forms of the infection. If this does not help, seek care from your doctor. You may need a prescription medication. Topical mupirocin ointment, available only by prescription, is highly successful in treating mild forms of the infection. Don't try over-the-counter antibacterial ointments; they are too weak to kill strep and staph infections, and applying the ointment carelessly may actually spread the impetigo. If you have more severe infection, you may need to take oral antibiotics.
Anyone in a household who develops impetigo should use a clean towel with each washing. Be sure to launder those towels separately. Keep sores covered to prevent spread of the infection to other parts of the body or other people.