Marty O. Visscher

Changes in Diapered and Nondiapered Infant Skin Over the First Month of Life

Abstract: Time‐ and site‐dependent differences in epidermal barrier properties were investigated over the first 28 days of life in healthy term newborn infants. Diapered and nondiapered skin sites were contrasted to the volar forearm of adults (mothers). Thirty‐one term infants were evaluated in the hospital on postnatal day 1 and at home on days 4, 7, 14, 21, and 28 for a total of six visits. Measurements included baseline skin hydration, continuous capacitive reactance, peak water sorption, rate of water desorption, skin pH, skin temperature, and environmental conditions. Changes in epidermal barrier properties over the first 4 weeks of life included an increase in surface hydration, a decrease in transepidermal water movement under occlusion, a decrease in surface water desorption rate, and a decrease in surface pH. Diapered and nondiapered regions were indistinguishable at birth but exhibited differential behavior over the first 14 days, with the diapered region showing a higher pH and increased hydration. Maternal measurements remained constant throughout the period. We conclude that healthy newborn skin undergoes progressive changes in epidermal barrier properties over the first 28 days. Adult skin testing does not replicate newborn skin during the first month of life.

Development of Diaper Rash in the Newborn

Abstract: Diaper rash is a common infant malady. This study documents the earliest stages of rash in a cohort of 31 healthy term newborns over the first 28 days of life. The diaper area was evaluated using a standardized diaper rash grading scale. The anal, buttock, genital, intertriginous, waistband, and leg areas were assessed separately. At birth the average grade was 0.1 and none of the infants had specific features of advanced rash. Nineteen percent had dryness and/or slight redness. By day 7, 71% of infants had some features of skin compromise, giving rise to an overall grade of 0.6. Both the frequency and overall grade increased during postnatal weeks 2 and 3. Overall scores for days 21 and 28 were the same (1.1). The perianal area had the highest overall regional rash grade. Gender differences were present for the genital area only. These findings indicate that epidermal barrier breakdown is an uncommon finding at birth. Clinical signs of irritated skin in the diaper area develop progressively over the first postnatal month. A better understanding of the mechanisms conferring epidermal barrier protection at birth may be important for developing skin care products and practices to extend this protection later into life.

Characterization of Vernix Caseosa as a Natural Biofilm: Comparison to Standard Oil‐Based Ointments

Abstract: The application of occlusive films and oil‐in‐oil ointments has been reported to improve epidermal barrier function in very low birthweight, preterm infants. Such infants have a structurally immature stratum corneum and lack a surface coating of vernix caseosa. In this study we examined the short‐term effects of topical application of vernix caseosa to human skin and contrasted these effects with commonly used ointments and water‐in‐oil emulsions. Specifically, vernix, Eucerin®, Aquaphor®, and petrolatum were applied to the volar skin surface of adult volunteers. Surface electrical capacitance (SEC) and transepidermal water loss (TEWL) were measured as indices of surface hydration. Sorption‐desorption profiles were performed to determine skin surface hydrophobicity. Particular attention was given to monitoring the acute (0–120 minutes) changes following vernix treatment in order to compare these effects with earlier reports on the rate of skin surface drying in newborn infants following birth. Immediately after vernix application there was an increase in the rate of water loss from the skin surface. Relative to control skin and skin treated with the ointments and water‐in‐oil emulsions, the application of vernix to freshly bathed human skin resulted in a unique profile of temporal change in baseline surface hydration, moisture accumulation, and water‐holding capacity. These results demonstrate major differences between human vernix and standard oil‐based topical ointments. The results provide a framework for discussing the various properties of topical barriers applied to the very low birthweight infant.

The biology of vernix caseosa

The biology and physical properties of the uniquely human skin cream ‘vernix caseosa’ are discussed. This material coats the foetal skin surface during the last trimester of gestation and provides multiple beneficial functions for the foetus and newborn infant. Vernix has a complex structure similar to stratum corneum but lacks lipid lamellae and is more plastic due to the absence of desmosomal constraints. In utero, vernix is made in part by foetal sebaceous glands, interacts with pulmonary surfactant, detaches into the amniotic fluid, and is swallowed by the foetus. At the time of birth, vernix has a remarkably constant water content approximating 80%. Postnatally, vernix is simultaneously a cleanser, a moisturizer, an anti‐infective, and an anti‐oxidant. Vernix facilitates acid mantle development and supports normal bacterial colonization. Its hydrated cellular structure and unusual lipid composition provide a ‘best’ solution for the needs of the foetus and newborn, not least of which is the attraction of caregivers. Vernix is an important natural biomaterial of potential interest to cosmetic scientists, and other disciplines involved in product development and therapies targeting the complex interface between the stratum corneum and a changing terrestrial environment.

Early adaptation of human skin following birth: a biophysical assessment

Background/aims: Successful adaptation to postnatal life requires rapid physiological transitions in multiple organ systems. Mechanisms regulating stratum corneum water interactions and evaporative heat loss, for example, are pivotal in making the transition from the warm, aqueous prenatal state to a cold, dry postnatal environment. Understanding these mechanisms is important in formulating skin care guidelines in early infancy.