Infant skin maturation: Preliminary outcomes for color and biomechanical properties.

BACKGROUND: Newborn infant skin changes after birth but studies have focused on the epidermal barrier. Dermal properties are relevant for care, but literature on postnatal changes is sparse. We further characterized skin maturational changes in lightness, color and response to biomechanical stress. METHODS: Normal skin sites from subsets of participants in a trial on the progression and stage of infantile hemangiomas were retrospectively examined. Standardized photographs were analyzed as L*, a*, and b* images. Biomechanics were measured with the Cutometer® . RESULTS: Color changed significantly with increasing age. Skin was darker and redder at 2.0 vs. 5.4, 8.5 and 12.8 months. Yellow color increased, with higher values at 12.8 vs. 2.0, 3.5 and 5.4 months. Chest tissue was consistently more elastic than arm and face sites, with significantly higher elasticity for the youngest and oldest age groups. Biological elasticity, elastic recovery, and total recovery were significantly greater for the oldest subjects. Viscoelasticity and elastic deformation were lower at 5.5 vs. 8.8 and 17.6 months. Arm viscoelastic creep was highest at 2.8 months. CONCLUSION: Skin maturation continues into year two. Increasing elasticity and decreasing viscoelasticity may reflect increased collagen structure/function. The findings have implications for prevention of skin injury associated with mechanical forces.

Biomechanical properties of infantile hemangiomas: clinical stage and effect of age.

BACKGROUND: Infantile hemangiomas (IHs) are benign vascular neoplasms with rapid capillary proliferation shortly after birth and slow involution with diminishing capillary proliferative activity, fibrosis, and fatty replacement over 7-10 years. METHODS: Hemangiomas and contralateral control sites in 88 subjects were measured using a suction device, 6-mm probe and 200 mbar negative pressure. Mechanical properties were assessed vs. controls and effects of body site, depth, clinical stage, histology diagnosis, and time. RESULTS: Biological elasticity, overall elasticity, net elasticity, total recovery, and elastic recovery were lower for IH vs. controls (P < 0.001). IH total deformation, elastic deformation, viscoelastic creep, and residual deformation were higher than controls (P < 0.001). Involuting IHs had lower viscoelasticity than proliferating and stable lesions (P < 0.001) and lower viscoelastic creep than stable IHs (P = 0.04). IH viscoelasticity was higher at 2.3 than 12.9, 23.7, and 61.0 months and at 4.9 and 8.1 than 61.0 months. IH elastic recovery varied by body site with larger differences vs. control for abdomen and leg. Elastic recovery differences from control were smaller at younger vs. older ages. CONCLUSIONS: Measurement of biomechanical properties may be useful to characterize IH progression and treatment response in clinical settings.

Neonatal intensive care practices and the influence on skin condition.

BACKGROUND: Premature skin has a thinner epidermis with a poorly formed stratum corneum (SC) barrier compared to full term skin. Poor skin integrity increases the risk of exposure to irritants and infectious agents. Interventions that facilitate skin maturation are essential. OBJECTIVE: The objective was to examine the effects of prematurity and time from birth on SC maturation and to identify factors that impact skin condition. METHODS: A retrospective review was conducted among 130 NICU patients. Skin regions were evaluated for erythema, rash, integrity and function. The effects of gestational age, time from birth, stool exposure, nutrition and diagnosis were examined. RESULTS: Three groups emerged: (i) premature and <38 weeks adjusted age; (ii) premature and >38 weeks adjusted age; and (iii) full term. Surprisingly, the premature infants exhibited lower perineal irritation and greater SC integrity (lower transepidermal water loss) than full terms (P < 0.05). Group 2 had a longer time before the first skin-stool contact. Chest skin pH showed maturational changes for Group 1 (P < 0.05) but did not change for premature Group 2 who was older at enrollment. Erythema was lower for infants using elemental formulas or total parenteral nutrition. CONCLUSIONS: Premature infants with early stool contact and high exposure, full term infants, and patients with congenital diaphragmatic hernia or trisomy 21 are at high risk for skin compromise and may benefit from prophylactic interventions to minimize compromise. Low stool exposure and greater time before the first stool contact appear to be protective against skin compromise.

Hand hygiene compliance and irritant dermatitis: a juxtaposition of healthcare issues.

Reduction and prevention of health care-associated infections is a worldwide priority with emphasis on increasing hand hygiene compliance. Repetitive exposure to hand hygiene products and procedures is a significant factor in the development of occupational irritant hand dermatitis. Compliance has been difficult to achieve often due to skin irritation. The introduction of alcohol hand rubs has positively influenced compliance but rates remain lower than required. Genetic and environmental factors to the frequency and severity of irritant contact dermatitis have been identified. Because of the skin's role in innate immunity, maintenance of epidermal integrity is a key strategy for reducing health care-associated infections. In this review, we examine the interdependence of the two issues and the challenges of simultaneously accomplishing both goals. We emphasize research conducted among healthcare workers in their clinical settings. The factors that influence skin integrity and the challenges in meeting both goals simultaneously are explored. Cosmetic scientists have played key roles in the development of improved skin care products, and the issues present an excellent opportunity for them to provide potentially life-saving contributions to health care.

Role of TNF-α polymorphism -308 in neurosensory irritation.

Neurosensory cutaneous discomfort in response to topical products is common, yet the relationship between symptoms such as stinging and visible irritation is currently unclear. The presence of a polymorphism at position -308 on the TNF-α gene has been associated with skin irritation, i.e., erythema, dryness. Individuals with a G to A transition (AA/GA genotypes) have a lower threshold to experimentally induced irritation than those with the wild type (G allele, GG genotype). We investigated the effect of this polymorphism on neurosensory irritation (NSI). DNA genotyping was used to determine the allele type amongst a population of health care workers. The neurosensory response to lactic acid and water on the nasolabial folds and hands was assessed using a quantitative lactic acid sting test. Both genotypes had a more intense response to lactic acid compared with water on the face. The AA/GA genotypes had directionally higher scores from lactic acid (P = 0.1) and significantly higher stinging intensities from water (P = 0.001) on the face. For the hands, stinging intensities were higher for lactic acid and water amongst the AA/GA genotypes (P = 0.03 and 0.006 respectively). NSI to lactic acid was significantly higher on the face than on the hands (P < 0.05). Our findings indicate that subjects with the A transition at position -308 on the TNF-α gene experience more intense NSI with common ingredients, i.e., lactic acid and water, than those with the wild type. TNF-α polymorphism -308 may account for some of the inter-individual variability in response to skin care practices.

Imaging skin: past, present and future perspectives.

Skin imaging modalities relevant to the range of skin conditions encountered in clinical settings are described with respect to the information provided, advantages and limitations, current status and indications for further development. The methods use the interaction of energy with the skin, penetrating to various depths in the stratum corneum, epidermis, dermis and subcutaneous layers. They include a detection system such as the retina, film or a digital array, and a processing system to deconstruct, analyze and interpret the information. Similarly, the areas of interest, or targets, have common features. The skin conditions deviate from the ideal or normal state with respect to skin integrity and function. The deviations include evidence of barrier disruption, inflammation, dispigmentation, and vascular change. The user of skin imaging is often interested in the extent and severity of disease. Part of the task in skin imaging is to establish the criteria for the normal condition. The review encompasses the past, present and future of visual assessment, photographic image collection, spectrophotometric techniques, noninvasive histology, and three dimensional scanning. The analytical techniques for processing and extracting specific parameters that inform about the underlying biological status are presented.

Mechanism of tyrosinase inhibition by deoxyArbutin and its second-generation derivatives.

BACKGROUND: Disorders, such as age spots, melasma and hyperpigmentation at sites of actinic damage, emanate from the augmentation of an increased amount of epidermal melanin. OBJECTIVES: The ineptness of current therapies in treating these conditions, as well as high cytotoxicity, mutagenicity, poor skin penetration and low stability of skin-depigmenting formulations led us to investigate new compounds that meet the medical requirements for depigmentation agents. We have shown previously that the tyrosinase inhibitor deoxyArbutin (dA) is a more effective and less toxic skin lightener than hydroquinone (HQ). METHODS: The efficacy and reversibility of dA and its derivatives on inhibiting tyrosine hydroxylase and DOPAoxidase was assessed using standard assays. RESULTS: dA and its second-generation derivatives inhibit tyrosine hydroxylase and DOPAoxidase activities of tyrosinase dose dependently thereby inhibiting melanin synthesis in intact melanocytes, when used at concentrations that retain 95% cell viability in culture. This depigmenting effect was completely reversible when the compounds were removed. Tyrosinase inhibition was also observed in vitro when tested using human and purified mushroom tyrosinase, establishing that they are direct enzyme inhibitors. Lineweaver-Burk reciprocal plot analysis using mushroom tyrosinase illustrated that dA and its derivatives are more robust competitive inhibitors than HQ, when tyrosine is used as substrate. CONCLUSIONS: Thus, dA and its second-generation derivatives, which inhibit melanogenesis at safe concentrations by specifically acting on the tyrosinase enzyme at a post-translational level, are promising agents to ameliorate hyperpigmented lesions or lighten skin.

Indicators of skin barrier integrity among newborns massaged with mustard oil in rural Nepal.

OBJECTIVE: The objective of this study was to determine the skin barrier changes during postnatal month 1 among infants receiving routine mustard oil massage in the humid conditions of rural Nepal. STUDY DESIGN: This was an observational study among 500 live-born neonates receiving mustard oil massage. Skin integrity such as erythema, rash, dryness, skin pH, stratum corneum protein concentration and transepidermal water loss was measured on days 1, 3, 7, 14 and 28. RESULTS: Erythema and rash increased (worsened) during weeks 1 and 2, then decreased over weeks 3 and 4. Skin pH (6.1±0.5 to 5.0±0.6) and stratum corneum protein (16.6±7.9 to 13.5±5.9 µg cm-2) decreased. Transepidermal water loss increased from 33.2±23.5 to 43.0±24.5 g m-2 h-1 at day 28. Skin pH and stratum corneum protein were higher for early versus late premature infants. CONCLUSION: Premature and full-term skin condition was generally poor especially during the first 2 weeks, improving thereafter. Maturational changes were evident.

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.

Atopic dermatitis and atopy in non-clinical populations.

A group of 523 individuals from the general population in the Denver, Colorado area responded to an advertisement for subjects with "problem skin" conditions, such as eczema, dry skin, rashes, etc. The subjects completed screening history information and were evaluated for various characteristics during an examination by a dermatologist. Of the entire population, 33% satisfied the criteria for atopic dermatitis. Another group, described as the generic atopy subset, emerged from the classification and constituted 23% of the total. Individuals in this subset typically had either a personal history of atopic disease or a limited family history. They lacked past or present evidence of flexural rash. A third group, totaling 44%, was classified as nonatopic. A relatively large percent of each of the three groups exhibited some clinical signs of dry skin (e.g., scaling, flakiness). This feature is believed to be due, at least in part, to the damaging effects of the cold, dry conditions in Denver, Colorado.

Gene transfer in human skin with different pseudotyped HIV-based vectors.

Pseudotyping lentiviral vector with other viral surface proteins could be applied for treating genetic anomalies in human skin. In this study, the modification of HIV vector tropism by pseudotyping with the envelope glycoprotein from vesicular stomatitis virus (VSV), the Zaire Ebola (EboZ) virus, murine leukemia virus (MuLV), lymphocytic choriomeningitis virus (LCMV), Rabies or the rabies-related Mokola virus encoding LacZ as a reporter gene was evaluated qualitatively and quantitatively in human skin xenografts. High transgene expression was detected in dermal fibroblasts transduced with VSV-G-, EboZ- or MuLV-pseudotyped HIV vector with tissue irregularities in the dermal compartments following repeated injections of EboZ- or LCMV-pseudotyped vectors. Four weeks after transduction, double-labeling immunofluorescence of beta-galactosidase and involucrin or integrin beta1 demonstrated that VSV-G-, EboZ- or MuLV-pseudotyped HIV vector effectively targeted quiescent epidermal stem cells which underwent terminal differentiation resulting in transgene expression in their progenies. Among the six different pseudotyped HIV-based vectors evaluated, VSV-G-pseudotyped vector was found to be the most efficient viral glycoprotein for cutaneous transduction as demonstrated by the highest level of beta-galactosidase expression and genome copy number evaluated by TaqMan PCR.

A novel role for vernix caseosa as a skin cleanser.

OBJECTIVES: Skin cleansing is a complex process involving endogenous and exogenous mechanisms. This study examines the role of vernix caseosa in the process of skin cleansing in the perinatal period. METHODS: Vernix was evaluated as an exogenously applied skin cleanser using digitized image analysis which quantified residual carbon particles following a standardized cleansing assay. In addition, the detachment of vernix from human cadaveric skin and Gore-Tex supports was investigated following timed exposures to a variety of commonly used commercial surfactants. Detachment was quantified spectrophotometrically as increased turbidity at 650 nm. RESULTS: Image analysis showed that exogenous application of vernix exhibited a cleansing capability comparable or superior to standard skin cleansers. Dose-dependent increases in solution turbidity (vernix detachment) were seen following exposure of vernix-covered Gore-Tex vehicles to sodium laureth sulfate, sodium lauryl sulfate, and cocamidopropyl betaine solutions. Similar results were seen with cadaveric skin. CONCLUSIONS: These results demonstrate a role for vernix caseosa as a skin cleanser. Previous views of vernix as a soil or skin contaminant at birth need to be reevaluated.

Development of diaper rash in the newborn.

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.

Changes in diapered and nondiapered infant skin over the first month of life.

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.

A survey of skin care practices for premature low birth weight infants.

PURPOSE: To provide baseline information about current skin care practices in premature low birth weight infants (< 1,000 gm birth weight) in typical NICUs within the U.S. DESIGN: Descriptive survey. SAMPLE: 104 hospitals with at least 2,500 deliveries per year and at least 20 Level III NICU beds. MAIN OUTCOME VARIABLES: Environmental conditions, bathing practices and products, adhesive products used to secure IVs and endotracheal tubes, skin protectants used with diaper rash, treatment systems for fragile preterm skin, and treatment systems for denuded skin. RESULTS: Most units surveyed based their premature low birth weight skin care protocols on a combination of gestational age and birth weight criteria. One-quarter of the units had no skin care protocols at all. Among the units, there was considerable practice variation with respect to common nursing procedures such as bathing, adhesive application, and wound care.

Characterization of vernix caseosa as a natural biofilm: comparison to standard oil-based ointments.

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(R), Aquaphor(R), 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.