Protection against dryness of facial skin: a rational approach.

Facial skin is unique in that it gets far more exposure to the external environment than skin on other areas of the body and paradoxically, because it contains the thinnest epidermis and stratum corneum, especially on the eye lid. Environmental attacks contribute to drying of facial skin and damage to the stratum corneum. In recent years, there has been an explosion of new products that contain ingredients that claim to benefit facial skin and protect against environmental damage. This review critically examines the scientific basis, rationale and evidence for inclusion of these ingredients in products for protection of facial skin.