詳しくは ― 日本人

Milia は、小さくて硬い白い隆起として現れる、ケラチンで満たされた良性の一過性嚢胞です。通常、顔に集中して現れますが、胸部上部、腕、外陰部など他の部位にもできることがあります。主に 2 つのタイプがあります。原発性稗粒腫は出生時に存在し、鼻、頭皮、まぶた、頬などに自然に発生します。また、稀な遺伝性皮膚疾患が原因で起こることもあります。二次性稗粒腫は、基礎となる皮膚の問題、薬剤使用、または皮膚外傷とともに現れます。
Milia (singular: milium) are benign and transient subepidermal keratin cysts that present as small firm white papules in various numbers most commonly distributed on the face, but they can also be present on other anatomical areas such as the upper trunk, extremities, and genital area (prepuce). The classification of milia includes primary and secondary. The vast majority of primary milia accounts for congenital milia that occur spontaneously and are present at birth, mainly over the nose, scalp, eyelids, cheeks, gum border (Bohn nodules), and palate (Epstein pearls). Still, there is another percentage of primary milia that may occur in association with certain rare genodermatoses (inherited genetic skin disorders) in children and adults. Meanwhile, secondary milia manifest in association with underlying skin pathology, medications, or skin trauma.