1.The damage is milky white or yellow, pinhead to rice grain size firm papules, top round, covered with very thin epidermis.

2. Secondary damage is mostly distributed around the original lesions, which can last for several years and fall off naturally without scar formation.

3. Individual damages may have calcium salt deposits, hard as cartilage, and dark yellow color when the damage is enlarged.

4. Most common on the face, especially eyelids, cheeks and forehead. It can also occur on the genitals in adults and is usually limited to the eyelids and temporal region in infants.