Let’s start with ways to differentiate milia, sebaceous hyperplasia and neonatal acne.
Milia
Milia are tiny (1-mm to 3-mm) papules found most often on the face, chin, and forehead - and less often on the trunk and extremeties. These epidermal inclusion cysts are a common finding in newborns. Note that there is no associated inflammation of the skin. Usually they are harmless and will go away on their own.