Erythema toxicum is a benign, asymptomatic, self-limiting skin eruption of unknown etiology that occurs in around half of newborns and generally presents during the first week of life.
The rash appears as combinations of macules, papules and pustules surrounded by erythema. It usually begins on the face, spreading to the chest, trunk and limbs with occasional scrotal involvement. The palms and soles are usually spared. The rash waxes and wanes, but all lesions have usually disappeared within 7-14 days. Secondary infection of the lesions is highly unusual.
No treatment is required. Parents should be reassured that this will not cause any long term problems.
References
https://dermnetnz.org/topics/toxic-erythema-of-the-newborn/
Parmar, T. Neonatal dermatology – the benign conditions, Don’t Forget the Bubbles, 2016