a milium ("plural" milia), also called a milk spot or an oil seed, is a clog of the eccrine sweat gland. it is a keratin-filled cyst that can appear just under the epidermis or on the roof of the mouth. milia are commonly associated with newborn babies but can appear on people of all ages. they are usually found around the nose and eyes, and sometimes on the genitalia, often mistaken by those affected as warts or other sexually transmitted diseases. milia can also be confused with stubborn whiteheads.