Properties of Skin in Chinese Infants: Developmental Changes in Ceramides and in Protein Secondary Structure of the Stratum Corneum

Trajectory of stratum corneum lipid subclasses in the first year of life and associations with atopic dermatitis: A prospective cohort study

BACKGROUND

Trajectories of stratum corneum (SC) lipid subclasses and their associations with infant atopic dermatitis (AD) are unclear. This study aimed to quantify the trajectories of 15 SC subclasses and carbon chain lengths and their associations with AD within 12 months.

METHODS

In total, 213 newborns were enrolled at birth with nonlesional skin samples collected from the inner forearm at birth, 42 days, 3, 6, and 12 months, respectively. Lesional skin samples were collected from 120 AD patients at clinic with the disease onset within the first year of life. Mass spectrometry was applied to assess relative contents of 12 ceramide (CER), three free fatty acid (FFA) subclasses, and average carbon chain length (CCL). AD incident within 1 year old was diagnosed by dermatologists according to UK criteria.

RESULTS

Sixty-four (30.0%) cases of ADs occurred in the cohort. All SC lipid subclasses and CCLs, but EOP varied significantly during the first year. AD infants showed lower NP but higher NS, NH, AP, hydroxy FFA, and CCL of FFAs compared with nonaffected infants. After normalization by age, the differences remained and were more pronounced in lesional skin of clinical AD infants compared with non-ADs. NS, NH, and CCL of FFAs in lesional skin of AD infants showed positive and significant correlations with the levels of transepidermal water loss at 3 month; some evidence supports a negative correlation for NP.

CONCLUSIONS

We provide an overview of developmental trajectories of 15 CER and FFA subclasses across the first year of healthy infants and a link between the imbalance of some subclasses with the development of AD.

Development and validation of the atopic dermatitis and infant skincare knowledge, attitude, and practice (ADISKAP 1.0) scale

Importance

Preserving skin health is crucial for atopic dermatitis control as well as for the thriving of children. However, a well-developed and validated tool that measures the knowledge, attitude, and practice of skin care is lacking.

Objective

To develop and validate the atopic dermatitis and infant skincare knowledge, attitude, and practice (ADISKAP 1.0) scale that measures parental health literacy on atopic dermatitis and skin care.

Methods

We conducted a review of the literature, a focus group (two dermatologists and 12 parents), and a panel discussion in order to generate the ADISKAP prototype. Two samples of parents with knowingly superior (dermatologists, n = 59) and inferior (general population, n = 395) knowledge traits participated in the validation of ADISKAP. Cronbach's alpha was reported as a measure of internal consistency, and the intraclass correlation coefficient (ICC) was calculated to assess the test-retest validity. The known-groups technique was used to evaluate construct validity.

Results

The ADISKAP scale contained 17 items after content and face validity validation. After removing items that displayed poor test-retest reliability (n = 4) and construct validity (n = 3), 12 items were retained in the ADISKAP 1.0.

Interpretation

ADISKAP 1.0 is a reliable and valid tool for assessing parental knowledge, attitude, and practice on infantile atopic dermatitis and skin care.

Trend of changes in epidermal biophysical properties in the Chinese aged 1 month to 17-year old

BACKGROUND

Although it is known that epidermal biophysical properties vary with age and gender, the changes in epidermal biophysical properties over the time from baby to adolescence have not been elucidated yet. In the present study, we assessed the trend of changes in transepidermal water loss rates (TEWL), stratum corneum hydration, and skin surface pH in Chinese children.

PARTICIPANTS AND METHODS

A total of 780 boys and 610 girls, aged 1 month to 17-year old, were enrolled in this study. TEWL and stratum corneum hydration on the forearm and the shin were measured with GPSkin Barrier, whereas skin surface pH was measured with portable skin pH meter.

RESULTS

Overall, TEWL and stratum corneum hydration levels decreased, whereas skin surface pH increased in children from 1-month old to 17-year old. Significant decline in TEWL was observed on both the forearm and the shin of girls, and the shin of boys aged 13-17-year old. Similarly, marked decline in stratum corneum hydration levels started at ages of 6-12-year old. In contrast, decline in skin surface pH was observed in both girls and boys aged one to 12-month old except on the forearm of boys. Afterward, skin surface pH remained either stable or slight increase except on the shin of boys aged >12 months to 3-year old.

CONCLUSIONS

These results demonstrate that both TEWL and stratum corneum hydration levels decrease, whereas skin surface pH increases in children aged 1 month to 17-year old. The changes in these biophysical properties vary with age, gender, and body site.

How do the skin barrier and microbiome adapt to the extra-uterine environment after birth? Implications for the clinical practice

The multiple protective functions of the skin derive from the interactions between epithelial skin and immune cells as well as the commensal microbiota. Developed in the last trimester of intra-uterine life, the skin barrier adapts dynamically after birth. Specific differences in the structure and physiology have been disclosed between infant and adult skin. The stratum corneum of infants is thinner and structured by thicker corneocytes with a more anisotropic surface in comparison to adult skin. Lower levels of the natural moisturizing factor and its constituents, together with the increased protease activity in the epidermis result in dry baby skin and ongoing adaptation of the desquamation to the extra-uterine environment. Infant epidermis is characterized by an accelerated proliferation rate and clinically competent permeability barrier in term neonates, despite the higher baseline values of transepidermal water loss in infants. The skin surface of newborns is less acidic, which could increase susceptibility to diaper and atopic dermatitis. Immediately after birth, skin is colonized by commensal bacteria-a process dependent on the mode of delivery and of major importance for the maturation of the immune system. Skin bacterial diversity and dysbiosis have been related to different pathology such as atopic and seborrheic dermatitis. This paper focuses on the ongoing structural, functional and biochemical adaptation of the human skin barrier after birth. We discuss the interactions on the 'skin barrier/ microbiota/ immune system' axis and their role in the development of competent functional integrity of the epidermal barrier.

In vivo analysis of the stratum corneum of Japanese neonates and infants using confocal Raman spectroscopy: a pilot study

BACKGROUND

Physiological skin properties of neonates and infants change drastically after birth and are implicated in the onset of atopic dermatitis and other diseases. Studies have measured physiological skin properties in infants; however, how these properties change over time remains unclear. No reports have measured ceramide in the stratum corneum of infants using confocal Raman spectroscopy; hence, we used it to measure the physiological properties of the skin, including ceramide, in infants.

MATERIALS AND METHODS

The water content and other factors in the skin of infants aged 0, 1, and 6 months were measured. All measurements were performed five times indoors at 22 ± 2°C and 50% ± 10% relative humidity in the middle of the calf at 4-µm distances, and their mean was calculated.

RESULTS

The water content of the area between the skin surface and superficial layers was the lowest in newborns as compared with other ages, and the deeper the skin layer, the higher the water content. The stratum corneum, evaluated using confocal Raman spectroscopy, was the thickest in newborns and gradually thinned with age. Its water content was the lowest in newborns. The levels of natural moisturizing factor, ceramide, and cholesterol were higher in newborns and tended to decrease with age.

CONCLUSION

This report is the first to evaluate ceramide in the stratum corneum of infants using confocal Raman spectroscopy and could help in conducting subsequent longitudinal measurements of physiological skin properties in neonates and infants.

Expert consensus on ceramides containing skincare in newborns and infants and potential mitigation of atopic dermatitis

INTRODUCTION

The vulnerable skin of neonates and infants is still developing anatomically and functionally and more susceptible to skin barrier disruption. The current consensus paper explores challenges in caring for neonates and infants' skin, skincare use and evaluates the role of ceramides (CERs) containing cleansers and moisturizers.

EVIDENCE AQUISITION

A panel of eight clinicians who treat neonates and infants developed a consensus paper on new-born and infant skin barrier integrity and CERs-containing skincare importance. The consensus process consisted of a modified Delphi technique. The selected information from the literature searches, coupled with the panel's opinion and experience, was used to adopt statements to provide clinical data for paediatric dermatologists, dermatologists, and paediatric healthcare providers who treat neonates and infants.

EVIDENCE SYNTHESIS

Increasingly, evidence supports skincare starting early in life, recognizing the benefits of ongoing daily use of non-alkaline cleansers and moisturizers to maintain skin barrier function. Skincare for neonates and infants should be safe, effective, and fragrance as well as sensitizing agent-free. Skincare with CERs may benefit the stratum corneum's lipid and water content.

CONCLUSIONS

When applied from birth onwards, gentle cleansers and moisturizers containing barrier lipids help maintain the protective skin barrier and soothe the skin with long-term moisturizing benefits.

A Randomized, Double-Blind, Placebo-Controlled Trial Assessing the Oral Administration of a Heat-Treated Lactobacillus paracasei Supplement in Infants with Atopic Dermatitis Receiving Topical Corticosteroid Therapy

BACKGROUND/AIMS

Atopic dermatitis (AD) is a common disease in infancy, for which topical steroids are the first-line therapy but have side effects. Innovative approaches are needed to reduce the burden of AD and corticosteroid usage in infants.

METHODS

The once-daily consumption of heat-treated probiotic Lactobacillus paracasei GM-080 or placebo for 16 weeks as supplementary approach to topical treatment with fluticasone propionate cream was compared in AD infants aged 4-30 months. Outcomes were SCORAD and its subscores, TEWL, Infants' Dermatitis Quality of Life Index (IDQOL), corticoid "sparing effect," CCL17/TARC, and IgE status.

RESULTS

SCORAD, objective SCORAD, itching, and IDQOL decreased significantly (p < 0.001) over the treatment period in both treatment groups. Slight decreases (ns) were noted in TEWL in lesional and unaffected skin and CCL17 levels. There were no differences between the treatment groups. Total IgE increased over the treatment period in both groups, with significantly higher increase in the heat-treated probiotic group (p = 0.038). There was no evidence of a corticoid "sparing effect" by the probiotic.

CONCLUSIONS

In this design, the probiotic L. paracasei was not beneficial as a complementary approach to topical corticosteroids in infants with AD. However, slight beneficial effects may have been masked by the moderate potency corticoid.

Infant Skin Barrier, Structure, and Enzymatic Activity Differ from Those of Adult in an East Asian Cohort

Skin physiology is dynamically changing over the first years of postnatal life; however, ethnic variations are still unclear. The aim of this study was to characterize infant skin barrier function, epidermal structure, and desquamation-related enzymatic activity as compared to that of adult skin in an East Asian population. The skin properties of 52 infants (3-24 months) and 27 adults (20-40 years) were assessed by noninvasive methods at the dorsal forearm and upper inner arm. Transepidermal water loss and skin surface conductance values were higher and more dispersed for infants compared to adults. Infant skin surface pH was slightly lower than adult on the dorsal forearm. The infant SC and viable epidermis were thinner compared to adults with differences that were site-specific. Although the chymotrypsin-like activity for infant skin was comparable to adult level, the caseinolytic specific activity was significantly higher for the infant cohort. These observations indicate a differently controlled pattern of corneocyte desquamation in infants. In conclusion, structural and functional differences exist between infant and adult skin in the East Asian population pointing to dynamic maturation of the epidermal barrier early in life.