Erythema toxicum neonatorum revisited.

Erythema toxicum neonatorum (ETN) is a common neonatal dermatologic disorder that usually is evident within the first 48 hours of life. Characteristic lesions include erythema, wheals, papules, and pustules. This transient rash resolves spontaneously without sequelae over the course of a week. Histologically, ETN shows an abundance of eosinophils. Although it has been recognized and described for centuries, the etiology and pathogenesis of ETN remain unclear.