Milia are tiny white bumps or pimples. They occur when dead, normally sloughed-off skin becomes trapped in small pockets at the surface of the skin or mouth. Milia are common in newborn infants and appear as pearly white bumps, most commonly across the upper cheeks, nose, and chin. They are also commonly seen on the faces of adults or in areas of trauma or inflammation.

Irritation of the skin by rough sheets or clothing may cause mild reddening around the bump, but the central portion remains white. Irritated milia are sometimes incorrectly referred to as "baby acne" (although it is not actually a form of acne).

As the surface of the white pearly bump wears away, the trapped dead skin is lost, and the bump disappears. Milia generally disappear after the first several weeks of life. In adults, milia may persist indefinitely.

This same type of cystic structure is seen on the gums and soft palate of newborn infants. In these mucous membranes, they are called Epstein's pearls. These lesions also disappear spontaneously.

• Whitish, pearly bump in the skin of newborns, typically across cheeks, nose, and chin
• Whitish, pearly bump on gums or roof of mouth