Morphology of lipid alterations in the epidermis: a review.

An overview of the morphological correlates of mammalian epidermal lipids and the cutaneous permeability barrier is provided. The following features are discussed: 1) ultrastructural characterization of the progressive lipid alterations accompanying normal stratum corneum (SC) formation; 2) effects of drugs/inhibitors that interfere with specific aspects of epidermal lipid metabolism; 3) lipid alterations in certain human skin disorders; 4) effects of selected topical emollients on SC lipid organization; and 5) potential pitfalls in interpretation of ultrastructural data in terms of cutaneous function and dysfunction.