Impetigo

Abstract

Impetigo, commonly known as impetigo contagiosa, is a staphylococcal, streptococcal, or combined infection characterized by discrete, thin-walled vesicles that rapidly become pustular and then rupture. The most common seasonal incidence is in the hot summer months. Rash occurs in parts of the body exposed, such as the face, hands, neck and limbs. The rash is contagious through self-inoculation or casual contact. Common sources of infection for children are pets, dirty fingernails, other children in schools and daycare centers, or crowded housing areas; for adults, common sources include infected children and self-inoculation from nasal or perineal carriage. Bullous impetigo characteristically occurs in newborn infants, though it may occur at any age. Usually no scalp lesions are present. The majority are caused by phage types 71 or 55 coagulase-positive S. aureus or a related group 2 phage type. Staphylococcal scalded skin syndrome (SSSS) is a generalized, confluent, superficially exfoliative disease, occurring most commonly in neonates and young children. Group 2 S. aureus, most commonly phage types 71 or 55, is the causative agent in most ssss cases. Superficial Staphylococcus aureus infections are associated with formation of exfoliative toxins, most commonly exfoliative toxins A (ETA) and B (ETB). The diseases associated with this mechanism are staphylococcal scalded skin syndrome (SSSS) and bullous impetigo. Susceptibility testing and molecular typing, including multilocus sequence typing, spa, agr typing, and toxin detection is assessed for all S. aureus isolates. The diagnosis of impetigo is usually made on clinical grounds. Applying antibiotic ointment as a prophylactic to sites of skin trauma will prevent impetigo in high-risk children attending daycare centers. Systemic antibiotics combined with topical therapy are advised. The effective antibiotic agents for patients with impetigo are cephalosporin, mupirocin, fusidic acid or vancomycin. All treatment should be given for 7 days. It is necessary to soak off the crusts frequently, after which an antibacterial ointment should be applied. If the lesions are localized, especially if facial, and are present in an otherwise healthy child, topical therapy may be effective as the sole treatment.