Males and females are affected equally. Rare cases have been reported at birth. Incidence rises with increasing gestational age and birth weight. Delayed onset rarely may occur in full-term and preterm infants up to age 14 days. Infants with ETN otherwise are healthy and lack systemic symptoms.
Recurrences are uncommon but have been reported up to the sixth week of life.
They tend to be mild in severity. Focus the physical examination on location, size, and distribution of macules, wheals, papules, and pustules on the skin. Note the absence of mucosal, palmar, or plantar involvement. ETN most commonly presents with a blotchy, evanescent, macular erythema, often on the face or trunk. The macules are irregular, blanchable, and vary in size.