Skin Physiology of the Neonate and Young Infant: A Prospective Study of Functional Skin Parameters During Early Infancy

Abstract

Although neonatal and adult epidermis are similar with respect to thickness and lipid composition, skin development is not complete at birth. Previous studies indicate that the skin undergoes a process of adaptation and maturation postnatally. Postnatal skin physiology has not yet been evaluated comprehensively in a prospective study. We assessed skin function parameters prospectively in a cohort of 202 healthy term neonates (98 boys) of Caucasian descent. Measurements were performed at 3 days, 4 weeks, and 12 weeks of age and at four different body sites (frontal area, cheek, volar forearm, and gluteal surface). The following parameters were assessed: skin surface pH, corneal layer hydration (capacitance), epidermal desquamation, and surface roughness. Data were presented in box and whisker plots. Our results were as follows. Surface pH decreased by 0.3-1.1 units (p < 0.001), while desquamation increased significantly during the observation period (p < 0.001), but only on the facial areas. There was a significant increase in stratum corneum hydration (p < 0.001) which was paralleled by decreasing skin roughness, indicating smoothing of the skin surface (p < 0.001). No significant differences were found between male and female infants. These findings reflect significant cutaneous adaptation processes, particularly during the neonatal period. Reference values for functional skin parameters may be helpful in delineating normal from pathologic skin conditions such as ichthyosis or atopic dermatitis at an early stage when intervention might help to prevent exacerbations. The usefulness of these reference values will have to be evaluated in clinical practice.

Vernix Caseosa in Neonatal Adaptation

“…The pH decrease following birth has been attributed to maturation of the enzymes responsible for the synthesis of acidic components. 25 Fox et al 26 suggested that the mechanism of postnatal acidification is established in early gestation and is influenced by environmental factors. Few studies have addressed the contribution of vernix caseosa to acid mantle development.…”

Effective use of transdermal drug delivery in children

“…In healthy, full-term neonates, a decrease (0.3 -1.1) in surface skin pH, increased desquamation on the face, a smoother skin surface, and an increase in SC hydration were noted during the first 3 months of life [42]. Another investigation also recorded that the skin surface pH fell from neutral to 5.0 -5.5 within two weeks of birth.…”

Skin Care in Young Children: Innovative Approaches

“…Кислотность (рН) младенческой кожи относительно нейтральна сразу после рождения, однако она значитель-но снижается в течение первых 1-4 дней и продолжает уменьшаться в первые 3 месяца [46]. Подкисление также необходимо для лучшего сцепления клеток рогового слоя за счет увеличения синтеза липидов [47], в то время как повышенная рН способствует нарушению целостности рогового слоя, повышая тем самым восприимчивость кожи к механическим повреждениям.…”