Bullous impetigo (pediatric) in Infant/Neonate
Bullous impetigo is a localized form of caused by exfoliative toxins (A and B) released by (phage group II) Staphylococcus aureus. These toxins cleave desmoglein 1, resulting in superficial blisters locally at the site of infection. It is primarily seen in children, especially infants, who lack antibodies against exfoliative toxins, and only rarely occurs in teenagers or young adults. Infection is spread by direct contact with colonized or infected individuals. Staphylococcus aureus often colonizes the nares, umbilicus, nails, and eyes; approximately 5% of S aureus has exfoliative toxin.
Bullous impetigo initially presents as flaccid bullae, which then rupture, leaving round erosions that become crusted. The disease commonly affects moist intertriginous areas such as the axillae, neck, and diaper area; the face; and the extremities. Constitutional symptoms and fever are rare and mild, if they occur.
In neonates, the infection often presents in the first 2 weeks of life. Full resolution typically occurs within 2-6 weeks. Rare progression to staphylococcal scalded skin syndrome can occur. Sometimes, bullous impetigo may result in serious infections like osteomyelitis, septic arthritis, pneumonia, and septicemia.
Disseminated bullous impetigo has been reported in patients with atopic dermatitis.
L01.03 – Bullous impetigo
399183005 – Impetigo bullosa
Differential Diagnosis & Pitfalls
- Erythema toxicum neonatorum – Usually noticed in the first few days of life. The lesions are erythematous macules or urticarial plaques topped with a 1-2 mm papule or pustule that spontaneously resolves within 1-2 days.
- Transient neonatal pustular melanosis – Presents in the immediate postnatal period and is characterized by vesiculopustules without associated erythema. The pustules rupture easily, leaving behind hyperpigmented macules that may be surrounded by a characteristic collarette of scale.
- Neonatal herpes simplex virus infection
- Candidiasis – Erythematous patches with typical satellite pustules in the intertriginous areas.
- Staphylococcal scalded skin syndrome
- Epidermolysis bullosa simplex – Formation of blisters following abrasion-type skin trauma, usually around the hands, diaper area, and feet.
- Sexual abuse – Cases have been reported of bullous impetigo affecting the vulvar region, leading to confusion with possible sexual abuse.