Snapshot A 10-day-old girl is brought to the pediatrician by her mother after noticing multiple blisters. The mother states that some of the blisters have ruptured and left behind a ring of crust. On physical examination there is two 3 cm lesions on her axillae and several smaller bullae without any erythema in the groin. A superficial wound culture grows Staphylococcus aureus. She is subsequently started on topical antibiotics. Introduction Clinical definition superficial contagious bacterial skin infection which can be divided into nonbullous impetigo (most common) which is caused by Staphylococcus aureus or group A streptococci bullous impetigo caused by Staphylococcus aureus toxin which is a localized form of staphylococcal scalded skin syndrome Epidemiology incidence 20.5 per 1000 person-years most common bacterial skin infection in children demographics occurs commonly in children most common pathogen Staphylococcus aureus group A streptococcus most common location on face and arms risk factors summer weather disruption of skin leading to secondary infection of nonbullous impetigo atopic dermatitis Pathophysiology superficial skin blister ruptures and forms a crust Prognosis survival with treatment very good Presentation Nonbullous impetigo physcal exam single red macule or papule → vesicle surrounded by erythema → honey-crusted pustules Bullous impetigo physical exam progression from vesicle → flaccid bullae without erythema → crusted erosion ruptured bullae with yellow collarette from crusts Studies Labs positive Gram stain positive superficial wound culture Differential Herpes simplex virus vesicles on erythematous base (bullous impetigo typically has no erythema) Pemphigus foliaceus erythema with scaling and crusting Treatment Medical topical antibiotics indications local involvement of disease oral antibiotics indications widespread involvement of disease Complications Spread to other members of the family impetigo is highly contagious cover open skin lesions Acute post-streptococcal glomerulonephritis 1-5% of patients with nonbullous impetigo