Juvenile colloid milium: clinical, histological and ultrastructural features.

We report the clinical, histological and ultrastructural features of juvenile colloid milium affecting a brother and sister. In this rare condition, translucent papules develop on sun-exposed areas of skin, with onset in childhood. Histologically and ultrastructurally, the papules consist of amyloid-like material derived from epidermal keratonocytes. A review of the literature suggests a possible genetic abnormality that leads to sun-induced degeneration of keratinocytes.