Impetigo: An Overview

This article reviews in detail the pathogenesis, clinical characteristics and management of impetigo in children. Impetigo is the most common bacterial skin infection of children. Most cases of nonbullous impetigo and all cases of bullous impetigo are caused by Staphylococcus aureus. The remainder of cases of nonbullous impetigo are due to group A beta hemolytic streptococci (GABHS). GABHS colonize the skin directly by binding to sites on fibronectin that are exposed by trauma. In contrast, S. aureus colonizes the nasal epithelium first; from this reservoir, colonization of the skin occurs. Patients with recurrent impetigo should be evaluated for carriage of S. aureus. Superficial, localized impetigo may be treated successfully in more than 90% of cases with topical application of mupirocin ointment. Impetigo that is widespread or involves deeper tissues should be treated with a beta-lactamase-resistant oral antibiotic. The choice of antibiotics is affected by the local prevalence of resistance to erythromycin among strains of S. aureus, antibiotic cost and availability, and issues of compliance.