Erythema toxicum neonatorum is a common, non-threatening rash in newborns. It appears in 4-70% of newborns within the first week of life, and it typically improves within 1-2 weeks. It only occurs during the newborn period, but may appear slightly later in premature babies. The rash has a variable appearance. It typically includes blotchy red spots, often with overlying firm, yellow-white bumps or pus-filled boils. There may be only a few or many lesions. The lesions can appear almost anywhere on the body, and individual lesions may appear and disappear within hours. There are no other symptoms associated with erythema toxicum neonatorum, and the rash does not have any long-term effects on the skin. Erythema toxicum neonatorum is not harmful and does not require any treatment.