A 12-day-old healthy male is brought to the emergency department by his parents because of a blistering groin rash and fever that started 24 hours ago. His Tmax over that time period was 101.7F. The parents report that the patient also has become increasingly fussy and has not eaten well over the past day. The patient has a normal birth history, is gaining weight well, and has no other issues. Examination is remarkable for a fussy but consolable child with a temperature of 101.3 and the rash seen in the image provided.
What is the diagnosis?
The clinical findings in this patient are consistent with bullous impetigo. The differential diagnosis includes insect envenomation, thermal burns, allergic contact dermatitis, or other bullae-producing dermatologic conditions. There were no known exposures in this patient, and the acute fever points to an infectious etiology for this rash. Bullous impetigo results from infection with epidermolytic toxin A-producing Staphylococcal aureus (which also causes staphylococcal scalded skin syndrome). Manifestations include flaccid bullae containing clear yellow or slightly turbid fluid with an erythematous halo arising from normal skin. The bullae form most commonly in intertriginous areas, such as the groin, as in this patient. Given this patient's age and fever, a full septic workup is indicated. This patient was admitted and treated with ampicillin, gentamycin, and vancomycin and ultimately did well.