Milia

Definition:

A superficial inclusion cyst in the skin or mucous membrane.

Causes, incidence, and risk factors:

Milia occurs when dead, normally sloughed skin is trapped in small, very superficial, cystic structures in the skin or mucous membrane. Milia is seen frequently in newborn infants and appears as pearly white bumps (papules) most commonly found across the upper cheeks, nose, and chin. Irritation of the skin by rough sheets or clothing may cause mild reddening around the papule, 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 papule wears away the trapped dead skin is lost and the papule disappears. Milia generally disappears after the first several weeks of life.

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