[Cutaneous hydration of the premature and new born]

The barrier function of the stratum corneum is a fundamental element in maintaining cutaneous hydration. Alteration in the stratum corneum leads to the loss of this barrier function, with increased transdermal water loss, decreased water content and installation of xerosis. Moisturizers correct cutaneous xerosis by restoring the stratum corneum. In the new born, the architectural and biochemical structure of the stratum corneum is identical to that of infants and adults. However, 60 p. cent of new born exhibit physiologic desquamation, demonstrating a transitory functional deficit in the stratum corneum, justifying emollient treatment. After this physiological desquamation period, emollients are reserved for atopic infants or those presenting keratinization disorders. In the premature, the epidermis and particularly the stratum corneum are immature; trans-epidermal water loss is elevated and the skin is dry or even fissural. The interest of applying emollients to the skin of premature new born was recently demonstrated. Emollients improved the aspect of the skin and also decreased the number of infectious episodes.