Transepidermal Water Loss Measurements Research Articles

Comparison of Transepidermal Water Loss in Preterm Newborns Treated with Two Different Types of Phototherapies.

To compare transepidermal water loss (TEWL) in preterm newborns treated with two different types of phototherapies. In this experimental randomized controlled study, participants were 60 preterm infants aged 30 to 36 weeks' gestation who were admitted to the neonatal ICU of Duzce University Research and Application Center from December 2015 to May 2016. Researchers randomly assigned the newborns to two phototherapy groups: light-emitting diode (LED) and fluorescent phototherapy. Each group included 30 participants. Data were collected using a demographic information form and an evaporimeter to measure TEWL levels. Prior to phototherapy, the anterior region TEWL values were 11.99 ± 3.04 and 11.56 ± 3.99 g/m2 per hour in the fluorescent and LED groups, respectively, and the posterior region TEWL values were 12.82 ± 3.94 and 12.42 ± 4.24 g/m2 per hour in the fluorescent and LED groups, respectively. Prior to phototherapy, anterior and posterior TEWL measurements did not differ either within or between groups. However, in comparison with fluorescent group participants, participants in the LED group experienced significantly less water loss at 30 minutes and 1, 3, 6, 12, and 24 hours after the start of phototherapy (P < .001). Fluorescent phototherapy causes more water loss than LED phototherapy in preterm infants, and TEWL values are similar in both anterior and posterior measurements.

Deficient functional wound closure as measured by elevated trans-epidermal water loss predicts chronic wound recurrence: An exploratory observational study

A single-center, prospective, observational pilot study was performed to evaluate wound healing endpoint and recurrence by measuring transepidermal water loss (TEWL) post-closure at the site of wound repair. Patients with clinically-defined chronic wounds (such as pressure ulcers, diabetic ulcers, and trauma wounds) who visited the Plastic Surgery outpatient department or were in-patients at the All India Institute of Medical Sciences, Rishikesh, India, and were referred for chronic wound management, were enrolled. Non-invasive point-of-care TEWL measurements were obtained, from closed wound-site and contralateral healthy skin site, starting from confirmation of closure (post-closure, V0) continuing every 2 weeks for a maximum of five visits or until the wound recurred. Statistical analyses of the data involved logistic regression and likelihood ratio chi-square tests to assess differences in TEWL at visit 0 (V0) between the closed wound site and reference skin, with the TEWL score as the sole predictor of recurrence. Of the 72 subjects that completed the study, 44 (61%) showed no recurrence and 28 (39%) had wounds that recurred over a period of 12 weeks. A significant association was found between the V0 (post-closure) TEWL score and the odds of wound recurrence, both in univariate analysis (OR [95%CI] = 1.26[1.14,1.42] (p < 0.001) and after adjusting for covariates in multivariable analysis (OR [95%CI] = 1.34[1.19,1.61] (p < 0.001). The likelihood ratio chi-square analysis demonstrated that the V0 TEWL score is a significant universal predictor of recurrence across all wound types studied. Cases of closed wounds with subsequent recurrence showed an overall higher post-closure V0 TEWL score, compared to those who did not have a wound recurrence, across visits. The TEWL score cut-off value predictive of recurrence was 24.1 g.m–2.h–1 (AUC = 0.967). The outcome of this pilot study on a wide range of chronic wounds leads to the hypothesis that post-closure TEWL at the site of wound healing is a reliable biomarker of wound recurrence. It also raises the question whether the clinical endpoint of wound closure should include re-establishment of skin barrier function as additional criterion. The current standard of care wound closure endpoint calls for re-epithelialization of the wound with no discharge for two consecutive weeks disregarding the functional parameter of restoration of skin barrier function at the wound-site.

Natural Skin Care Regimen Improves Clinical Parameters and Quality of Life in Children with Atopic Dermatitis

Background: Atopic dermatitis (AD) is a prevalent, chronic inflammatory skin disorder, characterized by xerosis, itching and recurrent eczematous lesions. The condition also has major psychosocial implications for patients and their families. A daily skincare regimen of gentle cleansing and moisturization is an important part of atopic dermatitis therapy. Objective: This study evaluated the tolerability and efficacy of a nature-based shampoo/wash and moisturizer in children with mild to moderate atopic dermatitis Methods: This open-label study involved 23 children (6 months – 13 years) with atopic dermatitis. A daily skin care regimen of nature-based shampoo/wash and moisturizer was used for 4 weeks. The primary endpoint was tolerability assessed through clinical grading of erythema, dryness and roughness. The study pediatrician graded the eczema condition using the Eczema Area and Severity Index (EASI), and assessments of stratum corneum hydration and transepidermal water loss were performed before and after treatment. Parent/guardian completed two validated quality of life questionnaires. Results: Twenty children completed the study. Clinical evaluations showed significant improvement in subjects’ atopic disease with daily use of nature-based regimen. Significant reduction in dryness and roughness was observed, indicating that both products were well-tolerated. Moisture content and transepidermal water loss measurements showed directional improvements in skin barrier function. Parent/guardian reported significant improvements in quality-of-life assessments. Conclusions: The study demonstrated that nature-based skin care regimen was well tolerated and improved quality of life and skin condition in children with atopic dermatitis and can be used either alone or in adjunction with traditional treatment for disease control.

Current trends and requirements in sensors for hydroxy acid-based skincare treatments: A mini-review

Hydroxy acids (HAs) play a pivotal role in skincare formulations that address dry skin, acne, and signs of aging by modulating skin keratinization. The effectiveness of HAs depends on precise application, concentration, and adaptability to individual skin types. The effect of HAs on the skin must be monitored to ensure safe, effective, and personalized skincare. This review highlights current sensor technologies for HA treatment of the skin, including measurements of pH, skin hydration, pigmentation, and transepidermal water loss. In addition, we explored key sensing elements related to HA application, such as Ca2+ concentration in the epidermis, hyaluronic acid levels, and glucose in the interstitial fluid, as well as the HA concentration in biofluids. We also highlighted the role of advanced sensor technologies in improving HA treatment and provided guidance to dermatologists and researchers regarding the use of cutting-edge methods. Finally, we discussed the emerging trends and prospects of sensor technologies, highlighting the synergy between artificial intelligence and multimodal sensing for the realization of smart, personalized at-home skincare solutions.

Biomonitoring of hand and forearm transepidermal water loss and skin pH among nursing apprentices.

Measurements of transepidermal water loss (TEWL) and stratum corneum (SC) pH can help indicate work-related skin barrier damage, but sensitivity to confounding personal and ambient factors limits their potential as biomonitoring tools. To evaluate the difference between hand and forearm skin barrier conditions as a tool for early recognition of workers with occupational contact dermatitis. The participants were nursing apprentices (N = 238, median age 19 years) from Zagreb, Croatia. They filled out a questionnaire based on the Nordic Occupational Skin Questionnaire, underwent a clinical examination of skin on the hands, and were evaluated for their TEWL and SC pH on the dorsum of the hand and volar part of the forearm. We found that the difference between hand and forearm TEWL values (ΔTEWL) greater than 7 g/m2/h, or >50%, or the difference in SC ΔpH >0.50, predicted visible skin changes found on clinical examination. However, only the association with ΔpH >0.50 retained statistical significance when controlled for sex, age, ambient temperature, and relative humidity in a multiple regression model. The difference between hand and forearm SC pH values is suggested as a reliable biomonitoring tool in recognition of damaged skin barrier conditions in occupational settings.

Difference between hand and forearm transepidermal water loss and skin pH as an improved method to biomonitor occupational hand eczema: our findings in healthcare workers.

The aim of this cross-sectional field study was to establish the condition of hand and forearm skin barrier among dentists and physicians and how it may be associated with personal and work-related factors. The study consisted of an occupational questionnaire, clinical examination of skin on hands, and transepidermal water loss (TEWL) and pH measurements on hands and forearms. The participants were divided in the following groups (N=37 each, N=148 in total): physicians, medical surgeons, dentists, and dental surgeons. We calculated the difference between hand and forearm TEWL and pH (ΔTEWL and ΔpH, respectively) and divided it by the forearm values (ΔTEWL% and ΔpH%, respectively). There was a clear trend of increasing median ΔTEWL%, starting from physicians with non-surgical specialisation (56 %) to medical surgeons (65 %), dentists (104 %), and dental surgeons (108 %), with the latter two groups showing particularly worrisome signs of work-related skin barrier impairment, since they had double the TEWL on hands than on forearms. Although less prominent, the same worsening trend was noted for skin pH, with dental surgeons having on average a 0.3 points higher skin pH on hands than on forearms. These findings were mainly associated with prolonged glove use and male sex. Our findings also suggest that comparing TEWL and pH between hands and forearms can better establish occupational skin barrier impairment on hands.

Papain Suppresses Atopic Skin Inflammation through Anti-Inflammatory Activities Using In Vitro and In Vivo Models.

Papain (PN) is a proteolytic enzyme derived from Carica Papaya L. While the pharmacological effects of PN have not been extensively studied compared to its enzymatic activity, PN also holds potential benefits beyond protein digestion. This study aimed to investigate the potential effects of PN against skin inflammation in house dust mite Dermatophagoides farinae body (Dfb)-exposed NC/Nga atopic dermatitis (AD) mice and human HaCaT keratinocytes and their underlying mechanisms. The effects of PN on the skin were assessed via histological examination, measurements of transepidermal water loss (TEWL), quantitative reverse transcription-polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. Our findings indicated that the oral intake of PN decreased the severity scores of lesions resembling AD, TEWL, and the levels of inflammatory cytokines and serum immunoglobulin E in Dfb-induced AD mice, along with a reduction in epidermal thickness and mast cell infiltration. Additionally, PN inhibited the activation of the mitogen-activated protein kinases (MAPKs) and the signal transducer and activator of transcription (STAT) pathways in Dfb-induced AD mice and HaCaT keratinocytes. Moreover, PN improved survival and reduced ROS production in H2O2-damaged HaCaT keratinocytes and enhanced the expression of antioxidant enzymes in Dfb-induced AD mice. Concludingly, the oral administration of PN suppressed inflammatory mediators and downregulated the MAPKs/STAT pathway, suggesting its potential role in AD pathogenesis.

Guselkumab treatment normalizes the stratum corneum ceramide profile and alleviates barrier dysfunction in psoriasis: results of a randomized controlled trial

The epidermal inflammation associated with psoriasis drives skin barrier perturbations. The skin barrier is primarily located in stratum corneum (SC). Its function depends on the SC lipid matrix of which ceramides constitute important components. Changes in the ceramide profile directly correlate to barrier function. In this study, we characterized the dynamics of the barrier function and ceramide profile of psoriatic skin during anti-Interleukin-23 therapy with guselkumab. We conducted a double-blind, randomized controlled trial in which 26 mild-to-severe plaque psoriasis patients were randomization 3:1–100 mg guselkumab or placebo for 16 weeks and barrier dynamics monitored throughout. Barrier function was measured by trans-epidermal water loss measurements. Untargeted ceramide profiling was performed using liquid chromatography-mass spectrometry after SC was harvested using tape-stripping. The barrier function and ceramide profile of lesional skin normalized to that of controls during treatment with guselkumab, but not placebo. This resulted in significant differences compared to placebo at the end of the treatment. Changes in the lesional ceramide profile during treatment correlated with barrier function and target lesion severity. Nonlesional skin remained similar throughout treatment. Guselkumab therapy restored the skin barrier in psoriasis. Concomitant correlations between skin barrier function, the ceramide profile, and disease severity demonstrate their interdependency.

Transepidermal water loss (TEWL) and transonychial water loss (TOWL) measurements in healthy nail apparatus.

Although non-invasive diagnostic methods are widely used to examine the nail apparatus (NA), studies in healthy ones are scarce, and analyzes were often conducted in small groups. In the literature, there are only a few reports on TOWL measurements. The results of TEWL studies in the proximal nailfold have not been published so far. Based on a detailed interview and physical examination, 81 volunteers (40 women and 41 men) aged from 22 to 65 years were qualified for the study. In this study, the overall examination of the NA in relation to water loss was performed for the first time, regarding the hand (d, dominant; n, non-dominant) and finger types (number, start of count from thumbs) as well as sex and age. The average TEWL value in the entire group ranged from 7.53 c.u. in the finger nd4 to 11.09 c.u. in nd1. Both in the dominant and non-dominant hand, in the entire analyzed group, and taking into account gender, weak statistically significant relationships were observed between the finger type value and TEWL (p<0.05).The TEWL values were lower moving away from the thumb, The average TOWL value in the entire group ranged from 5.01 c.u. in d1 to 7.34 c.u. in d5. Both in the dominant and non-dominant hand, in the entire analyzed group and considering gender, statistically significant relationships were observed between the type of finger and TOWL values (p<0.05). The TOWL values were higher moving away from the thumb. Subsequently, the values of TOWL and TEWL did not depend on type of hand (dominant or non-dominant), sex and age. Weak and moderate statistically significant correlations were found between TEWL and TOWL values in the entire study group and in females, as well as in selected fingers in males (d2, nd2, d3, nd3, d5, nd5) (p<0.05, r<0.27). Non-invasive diagnostics such TEWL and TOWL measurements are useful to assess differences in structure and function between types of fingers. However, obtained results demand further studies.

Comparison of Intact Fish Skin Graft and Allograft as Temporary Coverage for Full-Thickness Burns: A Non-Inferiority Study.

The extent and depth of burn injury may mandate temporary use of cadaver skin (allograft) to protect the wound and allow the formation of granulation tissue while split-thickness skin grafts (STSGs) are serially harvested from the same donor areas. However, allografts are not always available and have a high cost, hence the interest in identifying more economical, readily available products that serve the same function. This study evaluated intact fish skin graft (IFSG) as a temporary cover to prepare the wound bed for STSG application. Thirty-six full-thickness (FT) 5 × 5 cm burn wounds were created on the dorsum of six anesthetized Yorkshire pigs on day -1. To mimic the two-stage clinical situation, on day 0, wounds were excised down to a bleeding wound bed and a temporary cover (either IFSG or cadaver porcine skin) was applied; then, on day 7, wounds were debrided to a viable wound bed prior to the application of autologous 1.5:1 meshed STSG (mSTSG). Rechecks were performed on days 14, 21, 28, 45, and 60 with digital images, non-invasive measurements, and punch biopsies. The IFSG created a granulated wound bed receptive to the application of an mSTSG. FT burn wounds treated with an IFSG had similar outcome measures, including contraction rates, trans-epidermal water loss (TEWL) measurements, hydration, and blood perfusion levels, compared to cadaver skin-treated burn wounds. Pathology scoring indicated significant differences between the allograft- and IFSG-treated wounds on day 7, with the IFSG having increased angiogenesis, granulation tissue formation, and immune cells. Pathology scoring indicated no significant differences once mSTSGs were applied to wounds. The IFSG performed as well as cadaver skin as a temporary cover and was not inferior to the standard of care, suggesting the potential to transition IFSGs into clinical use for burns.

Frequent oil baths and skin barrier during infancy in the PreventADALL study.

In the general population randomized controlled trial PreventADALL, frequent emollient bath additives from 2 weeks of age did not prevent atopic dermatitis, while the effect on skin barrier function throughout infancy is not established. The primary aim of this exploratory substudy was to assess the effect of mineral-based oil baths on transepidermal water loss (TEWL) and dry skin through infancy, and secondarily to explore if filaggrin (FLG) mutations modified the effect. Overall, 2153 infants were included and randomized to either the 'Skin intervention' (SI) group (n = 995) (oil bath 4 times weekly from 2 weeks through 8 months) or 'No skin intervention' (NSI) group (n = 1158), with TEWL measurements at 3, 6 and/or 12 months of age. Information on FLG mutation status was available for 1683 of these infants. Effects of the skin intervention on TEWL and dry skin through infancy were assessed by mixed-effects regression modelling. Background characteristics and protocol adherence were collected from electronic questionnaires, birth records and weekly diaries. The TEWL (95% confidence interval) was on average 0.42 g m-2 h-1 (0.13-0.70, P = 0.004) higher in the SI group compared with the NSI group through the first year of life, with significantly higher levels at 3 months [8.6 (8.3-9.0) vs. 7.6 (7.3-7.9)], but similar at 6 and 12 months. Dry skin was observed significantly more often in the NSI group compared with the SI group at 3 months (59% vs. 51%) and at 6 months of age (63% vs. 53%), while at 12 months of age, the difference was no longer significant. At 3 months, the TEWL of FLG mutation carriers was similar to the TEWL in the SI group. No interaction between SI and FLG mutation was found in the first year of life. Infants given frequent oil baths from 2 weeks of age had reduced skin barrier function through infancy compared with controls, largely attributed to higher TEWL at 3 months of age, while the skin at 3 and 6 months appeared less dry in infants subjected to the skin intervention.

Emulsions containing allantoin and D-panthenol as attractive moisturizing agents

Dry skin is the common problem affecting people which triggers many unpleasant symptoms such as roughness, peeling, burning, itching and greater sensitivity to injury and external conditions. One method to assess the water loss of skin is transepidermal water loss (TEWL) measurement. Various active substances, for instance allantoin and D-panthenol, can be used to overcome the symptoms of the dry skin. In this study, emulsions containing allantoin and D-panthenol as moisturizing agents and various oils (liquid paraffin, Cannabis sativa, Baobab and Coconut oil) were developed. The prepared emulsions were characterized by: visual and microscopic appearance and pH values. Stability analysis was conducted by centrifuge test and sensory test using sensory sensation was evaluated. Rheological experiments were performed using a rheometer, while mechanical and adhesion tests by texture analyzer. TEWL values were measured using a tewameter, after application of the emulsions to the responders skin. TEWL study noticed that regular permanent use of moisturizing emulsions with allantoin and D-panthenol limited the water loss. In conclusion, it can be stated that emulsions containing allantoin and D-panthenol as active agents and Coconut oil as oily ingredient are attractive formulations with moisturizing effect and good application features.

Skin Barrier Function Assessment: Electrical Impedance Spectroscopy Is Less Influenced by Daily Routine Activities Than Transepidermal Water Loss.

Skin barrier function assessment is commonly done by measuring transepidermal water loss (TEWL). An important limitation of this method is the influence of intrinsic and extrinsic factors. Electrical impedance spectroscopy (EIS) is a lesser-established method for skin barrier function assessment. Some influential factors have been described, but no guidelines exist regarding the standardization of these measurements. To evaluate the effect size of daily routine activities on TEWL and EIS, as well as their correlation with age and anatomical differences. Healthy participants (n=31) were stratified into three age groups (18-29, 30-49, and ≥50 years). In a climate-controlled room, EIS and TEWL measurements were performed on the left and right volar forearm and abdomen. Body cream application decreased TEWL and EIS values after 15 and 90 minutes. Skin washing decreased TEWL for 15 minutes and EIS values for at least 90 minutes. TEWL was increased 5 minutes after moderate to intense exercise. Coffee intake increased TEWL on the abdomen after 60 minutes. TEWL and EIS values did not correlate with participants' age and no anatomical differences were observed. No correlation was observed between TEWL and EIS. Body cream application and skin washing should be avoided at least 90 minutes prior to measurements of TEWL and EIS. Exercise and coffee intake should also be avoided prior to TEWL measurements. EIS may be a promising tool for skin barrier function assessment as it is less affected by daily routine activities than TEWL.

Comparison of skin barrier abnormalities and epidermal ceramide profiles among three ω-O-acylceramide synthesis-deficient mouse strains

BackgroundThe epidermis contains many structurally diverse ceramides, which form the skin permeability barrier (skin barrier). Mutations in genes involved in the synthesis of ω-O-acylceramides (acylceramides) and protein-bound ceramides cause ichthyosis. ObjectiveWe aimed to elucidate the relationship between the degree of skin barrier impairment and changes in epidermal ceramide profiles caused by mutations in acylceramide synthesis genes. MethodsKnockout (KO) mice of three genes—fatty acid (FA) ω-hydroxylase Cyp4f39 (human CYP4F22 ortholog), FA elongase Elovl1, and acyl-CoA synthetase Fatp4—were subjected to transepidermal water loss measurement, toluidine blue staining, and epidermal ceramide profiling via liquid chromatography coupled with tandem mass spectrometry. ResultsTransepidermal water loss was highest in Cyp4f39 KO mice, followed by Elovl1 KO and Fatp4 KO mice, and Cyp4f39 KO mice also showed the strongest degree of toluidine blue staining. In Cyp4f39 KO, Elovl1 KO, and Fatp4 KO mice, acylceramide levels were 0.6%, 1.6%, and 12%, respectively, of those in wild-type mice. Protein-bound ceramide levels were 0.2%, 30%, and 33%, respectively, of those in wild-type mice. We also observed a near-complete absence of ω-hydroxy ceramides in Cyp4f39 KO mice, reduced total ceramide levels and shortened FA moieties in Elovl1 KO mice, and increased hydroxylated ceramide levels and slightly shortened FA moieties in Fatp4 KO mice. ConclusionsThe degree of reduction in protein-bound ceramide levels is probably related to the severity of skin barrier defects in these three strains. However, reduced acylceramide levels and other changes in ceramide composition unique to each KO strain are also involved.

432 Fluctuations in Equine Cutaneous Ph and Trans-Epidermal Water Loss Associated with Anatomical Location, Time, and Weather

Abstract Although skin health is of critical importance for all horse owners, understanding of cutaneous pH and trans-epidermal water loss (TEWL) and the normal ranges of these variables is lacking. Cutaneous pH and TEWL measures provide insight into the barrier function of the epidermis and have the potential to determine the resident dermal microbiota. However, these measures have been recorded to fluctuate due to a variety of factors such as environment and anatomical locations in other species. Accordingly, the objectives of this study were to identify the impacts of anatomical location, weather, and time of day on cutaneous pH and TEWL in equines. This study utilized nine (n = 9) stock type mares, group-housed in a pasture setting at Southern Illinois University Equine Center. Researchers measured cutaneous pH and TEWL three times (6:00 AM, 12:00 PM, 6:00 PM) daily across five anatomical locations (nose, whither, heart-girth, mid-back, and base of tail) for five consecutive days. All statistical analysis was conducted using SAS On Demand for Academics (P &amp;lt; 0.05). Analysis of changes in variables associated with time, anatomical location, and day were conducted utilizing a PROC GLM three-way repeated measures ANOVA utilizing a Greenhouse-Geiser correction. Cutaneous pH results displayed significant main effects of day (P = 0.0052) and time (P = 0.0073) as well as a significant interaction of day and location (P = 0.0004). Mean cutaneous pH fluctuated daily, however, certain anatomical locations fluctuated more than others each day. Additionally, pH was highest in the morning (mean of 7.28) and lowest in the evening (mean 7.011). However, the mean overall pH for the study is 7.14 which is congruent with other work. TEWL measurements had significant main effects of day (P &amp;lt; 0.0001), time (P &amp;lt; 0.0001), and location (P = 0.0231), as well as a significant interaction of day, time, and location (P &amp;lt; 0.0001). TEWL measurements fluctuated with day, likely a result of weather changes. Mean TEWL measurements were less in the morning (mean 24.68) and greatest in the afternoons (mean 38.52). Overall mean TEWL measurement was 30.25. The results of this work indicate fluctuations in dermal barrier variables are associated with day, anatomical location, and time of day. These findings may have implications for applications of dermal treatments for horses as well as catalog the natural fluctuations which may affect future research.

Effects of 1,3-propanediol associated, or not, with butylene glycol and/or glycerol on skin hydration and skin barrier function.

This study aimed to assess the effect of 1,3-propanediol at different concentrations (5%, 10%, or 15%), either applied alone or in combination with butylene glycol (BG) (5%) and/or glycerol (5%), on skin hydration and skin barrier function. The measurements were conducted using capacitance to determine skin hydration and trans epidermal water loss (TEWL) rates to evaluate skin barrier function. A total of 30 healthy female subjects participated in the study. Capacitance and TEWL measurements were conducted at multiple time points, including before application and at 15 min, 2 and 8 h after the humectants were applied to the forearms of the subjects. All the subjects provided written informed consent. The 1,3-propanediol in all concentrations and in all combinations (with BG and/or glycerol) increased skin hydration and improved skin barrier function 15 min, 2 and 8 h after application. Glycerol increased the hydration performance of 1,3-propanediol. The application of 1,3-propanediol at a concentration of 15%, either alone or in combination with other humectants, reduced the TEWL to a greater extent than lower concentrations of 1,3-propanediol. Furthermore, the addition of glycerol to 1,3-propanediol 15% improved the skin barrier and reduced TEWL when compared with 1,3-propanediol alone and with the combination of 1,3-propanediol + BG. The humectants significantly improved skin hydration and reduced TEWL throughout the 8-h time course. The increase in 1,3-propanediol concentration, as well as its combination with glycerol, provided a greater benefit to the skin, improving both hydration and the skin barrier function.

Household laundry detergents disrupt barrier integrity and induce inflammation in mouse and human skin.

Epithelial barrier impairment is associated with many skin and mucosal inflammatory disorders. Laundry detergents have been demonstrated to affect epithelial barrier function in vitro using air-liquid interface cultures of human epithelial cells. Back skin of C57BL/6 mice was treated with two household laundry detergents at several dilutions. Barrier function was assessed by electric impedance spectroscopy (EIS) and transepidermal water loss (TEWL) measurements after the 4 h of treatments with detergents. RNA sequencing (RNA-seq) and targeted multiplex proteomics analyses in skin biopsy samples were performed. The 6-h treatment effect of laundry detergent and sodium dodecyl sulfate (SDS) was investigated on ex vivo human skin. Detergent-treated skin showed a significant EIS reduction and TEWL increase compared to untreated skin, with a relatively higher sensitivity and dose-response in EIS. The RNA-seq showed the reduction of the expression of several genes essential for skin barrier integrity, such as tight junctions and adherens junction proteins. In contrast, keratinization, lipid metabolic processes, and epidermal cell differentiation were upregulated. Proteomics analysis showed that the detergents treatment generally downregulated cell adhesion-related proteins, such as epithelial cell adhesion molecule and contactin-1, and upregulated proinflammatory proteins, such as interleukin 6 and interleukin 1 beta. Both detergent and SDS led to a significant decrease in EIS values in the ex vivo human skin model. The present study demonstrated that laundry detergents and its main component, SDS impaired the epidermal barrier in vivo and ex vivo human skin. Daily detergent exposure may cause skin barrier disruption and may contribute to the development of atopic diseases.

Efficacy of a Cosmetic Treatment in Decreasing the Mild-to-Moderate Atopic Dermatitis in Babies, Children, and Adults: A Pilot Study

Atopic dermatitis (AD) is a chronic inflammatory and pruritic skin disease with a worldwide progressive increase in its incidence. In this clinical study, we studied the effect of a cosmetic treatment composed of a cleanser, and a body and face cream, on subjects (babies, children, and adults) suffering from mild-to-moderate AD. The product effect on AD clinical signs was investigated by SCORing Atopic Dermatitis (SCORAD) index, subjective evaluation, skin erythema index, and transepidermal water loss (TEWL) measurements. The products were shown to be effective in improving the AD scoring by SCORAD in all the groups, and a trend towards the decrease of the erythema index and the TEWL in the adult population. An improvement in itching sensation, skin redness, and skin dryness scoring was also reported by the subjects. Results from this study demonstrate the efficacy of the tested products in decreasing the overall AD severity through 28 days of treatment. Overall, the first results occurred within 14 days of treatment.

Transepidermal water loss rises before food anaphylaxis and predicts food challenge outcomes.

Food allergy (FA) is a growing health problem requiring physiologic confirmation via the oral food challenge (OFC). Many OFCs result in clinical anaphylaxis, causing discomfort and risk while limiting OFC utility. Transepidermal water loss (TEWL) measurement provides a potential solution to detect food anaphylaxis in real time prior to clinical symptoms. We evaluated whether TEWL changes during an OFC could predict anaphylaxis onset. Physicians and nurses blind to TEWL results conducted and adjudicated the results of all 209 OFCs in this study. A study coordinator measured TEWL throughout the OFC and had no input on OFC conduct. TEWL was measured two ways in two separate groups. First, TEWL was measured using static, discrete measurements. Second, TEWL was measured using continuous monitoring. Participants who consented gave blood before and after OFCs for biomarker analyses. TEWL rose significantly (2.93 g/m2/h) during reactions and did not rise during non-reacting OFCs (-1.00 g/m2/h). Systemic increases in tryptase and interleukin-3 were also detected during reactions, providing supporting biochemical evidence of anaphylaxis. The TEWL rise occurred 48 minutes earlier than clinically evident anaphylaxis. Continuous monitoring detected a significant rise in TEWL that presaged positive OFCs, but no rise was seen in OFCs with no reaction, providing high predictive specificity (96%) for anaphylaxis against non-reactions 38 minutes prior to anaphylaxis. During OFCs, a TEWL rise anticipates a positive clinical challenge. TEWL presents a novel monitoring modality that may predict food anaphylaxis and facilitate improvements in OFC safety and tolerability.

Exosome from IFN-γ-Primed Induced Pluripotent Stem Cell-Derived Mesenchymal Stem Cells Improved Skin Inflammation and Barrier Function.

The pathogenesis of atopic dermatitis (AD) is multifactorial, including immune dysregulation and epidermal barrier defects, and a novel therapeutic modality that can simultaneously target multiple pathways is needed. We investigated the therapeutic effects of exosomes (IFN-γ-iExo) secreted from IFN-γ-primed induced pluripotent stem cell-derived mesenchymal stem cells (iMSC) in mice with Aspergillus fumigatus-induced AD. IFN-γ-iExo was epicutaneously administered to mice with AD-like skin lesions. The effects of IFN-γ-iExo treatment were investigated through clinical scores, transepidermal water loss (TEWL) measurements, and histopathology. To elucidate the therapeutic mechanism, we used an in vitro model of human keratinocyte HaCaT cells stimulated with IL-4 and IL-13 and performed extensive bioinformatics analysis of skin mRNA from mice. The expression of indoleamine 2,3-dioxygenase was higher in IFN-γ primed iMSCs than in iMSCs. In human keratinocyte HaCaT cells, treatment with IFN-γ-iExo led to decreases in the mRNA expression of thymic stromal lymphopoietin, IL-25, and IL-33 and increases in keratin 1, keratin 10, desmoglein 1, and ceramide synthase 3. IFN-γ-iExo treatment significantly improved clinical and histological outcomes in AD mice, including clinical scores, TEWL, inflammatory cell infiltration, and epidermal thickness. Bioinformatics analysis of skin mRNA from AD mice showed that IFN-γ-iExo treatment is predominantly involved in skin barrier function and T cell immune response. Treatment with IFN-γ-iExo improved the clinical and histological outcomes of AD mice, which were likely mediated by restoring proper skin barrier function and suppressing T cell-mediated immune response.