Oral and topical supplementation of linoleic acid and skin disease

Intercellular lipids of the stratum corneum play a major role in modulating the efficiency of barrier function and in preventing skin disease. Cholesterol, sphingolipids, ceramides and free fatty acids constitute these lipids. Linoleic acid, being a constituent of ceramides, is a fundamental precursor necessary for lipid bilayer formation; furthermore, it is also involved in the formation of prostaglandins and other mediators controlling the development and the regulation of cutaneous inflammatory processes. Indeed, it has been shown in animal models that essential fatty acid (EFA) free diet induces the appearance of dry and eczematous skin. On the other hand, in these animals oral supplementation with these lipids restores normal barrier function and skin appearance. Atopic children, characterized by infantile seborrehic dermatitis and reduced blood levels of linoleic acid, normalize transepidermal water loss after topical application of EFA based products. Reduced production of omega-3 derivatives and eicosapentaenoic acid has been also shown to be relevant in the onset of psoriatic lesions in prone subjects. Oral supplementation of essential fatty acids provides in patients affected by eczematous and psoriatic skin a useful tool to improve skin condition.