Assessment of the Vehicle for Roflumilast Cream Compared to a Ceramide-Containing Moisturizing Cream in Mild Eczema.

BACKGROUND: Inflammatory dermatologic conditions suitable for topical treatments benefit from a hydrating vehicle that improves the skin barrier without irritation. OBJECTIVE: This research was designed to assess skin barrier effects and aesthetic attributes of the vehicle for topical roflumilast cream (vehicle) vs a currently marketed ceramide-containing moisturizing cream (moisturizer). METHODS: This was a single-site, randomized, intraindividual, double-blind, controlled study conducted over 17 days. Patients (aged 18 years or older) with mild, symmetric asteatotic eczema of the lower extremities were enrolled to receive lower leg applications of the vehicle on one leg and moisturizer on the other. The primary efficacy endpoint was a change in transepidermal water loss (TEWL) from baseline to day 15. Secondary efficacy endpoints included change from baseline in TEWL at other study visits, change from baseline in hydration as assessed via corneometry, and patient- and investigator-rated assessments of the products. Safety and tolerability were also assessed. RESULTS: A total of 40 patients enrolled in the study. The primary efficacy endpoint was met for both treatments. A statistically significant difference in TEWL on day 1 favored the moisturizer, but no difference was seen between vehicle and moisturizer at any other timepoint. Both vehicle and moisturizer also met the secondary efficacy endpoint of change from baseline in hydration. LIMITATIONS: The sample size was small. CONCLUSIONS: The vehicle for roflumilast cream performed similarly to a leading, currently marketed, dermatologist-recommended, ceramide-containing moisturizer across all patient- and investigator-rated assessments of efficacy, tolerability, and aesthetic properties in patients with mild asteatotic eczema. J Drugs Dermatol. 2024;23(10):834-840. doi:10.36849/JDD.7958  .

Novel Cosmetic Ingredient CS-AA Polyion Complex and Skin Moisturizing Effect.

PURPOSE: The study explored the enhanced skin moisturizing capabilities and moisture retention effects achieved by forming a polyion complex using sulfated glycosaminoglycan (GAG), specifically chondroitin sulfate (CS), and amino acids (AA) such as glutamine (Q) and arginine (R). The overall hydration effect of this CS-AA complex was examined. METHODS: After analyzing the CS-AA polyion complex structure using spectroscopic methods, the ex vivo moisture retention ability was assessed under dry conditions using porcine skin samples. Additionally, the efficacy of the CS-AA polyion complex in reducing transepidermal water loss (TEWL) and improving skin hydration was evaluated on human subjects using a digital evaporimeter and a corneometer, respectively. RESULTS: Validating a systematic reduction in particle size, the following order was observed: CS > CS/AA simple mixture > CS-AA complex based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) analysis. Furthermore, observations revealed that the CS-AA complex exhibits negligible surface charge. Additionally, Fourier-transform infrared spectroscopy (FT-IR) analysis demonstrated a distinct peak shift in the complex, confirming the successful formation of the CS-AA complex. Subsequently, the water-holding effect through porcine skin was assessed, revealing a notable improvement in moisture retention (weight loss) for the CS-Q complex: 40.6% (1 h), 20.5% (2 h), and 18.7% (4 h) compared to glycerin. Similarly, the CS-R complex demonstrated enhancements of 50.2% (1 h), 37.5% (2 h), and 33% (4 h) compared to glycerin. Furthermore, TEWL improvement efficacy on human skin demonstrated approximately 25% improvement for both the CS-Q complex and CS-R complex, surpassing the modest 12.5% and 18% improvements witnessed with water and glycerin applications, respectively. Finally, employing a corneometer, hydration changes in the skin were monitored over 4 weeks. Although CS alone exhibited nominal alterations, the CS-Q complex and CS-R complex showed a significant increase in moisture levels after 4 weeks of application. CONCLUSION: In this study, polyion complexes were successfully formed between CS, a sulfated GAG, and AA. Comparisons with glycerin, a well-known moisturizing agent, confirmed that the CS-AA complex exhibits superior moisturizing effects in various aspects. These findings suggest that the CS-AA complex is a more effective ingredient than CS or AA alone in terms of efficacy.

Postoperative risk assessment of post-inflammatory hyperpigmentation and the efficacy of delayed prevention following 532 nm Q-switched Nd:YAG laser treatment of solar lentigines: a randomized controlled study.

BACKGROUND: Although post-inflammatory hyperpigmentation (PIH) is a common adverse event following laser procedures, studies evaluating its risk remain limited. OBJECTIVE: To analyze PIH risk after 532 nm Q-switched Nd:YAG laser (QSNYL) treatment for solar lentigines and examine the efficacy of triple combination cream (TCC) for its prevention. METHODS: In this single center, investigator-blinded, randomized controlled study, participants with solar lentigo either received TCC or emollient from 2 weeks post-QSNYL treatment. The occurrence of PIH was determined by three independent and blinded dermatologists. In vivo skin measurements and sun exposure questionnaires were examined to evaluate the risk of PIH. RESULTS: A total of 28 patients with 67 solar lentigines were included in the analysis. In the control group, PIH occurred in 55.3% of the lesions. Risk factors for the occurrence of PIH were the increased erythema at weeks 2 (OR, 1.32; p = 0.035) and outdoor activity during 1-5 pm (OR, 8.10; p = 0.038). Treatment with TCC from 2 weeks post-QSNYL treatment significantly decreased the incidence of PIH (31.0% vs. 55.3%, p = 0.048). CONCLUSION: Post-laser erythema and outdoor activity at the daytime are prognostic factors for the occurrence of PIH. Administering TCC could be considered for the prevention of PIH in high-risk patients.

Enhancing topical delivery of ISRIB: Optimizing cream formulations with chemical enhancers and pH adjustment.

Chemical warfare agents, particularly vesicants like lewisite, pose a threat due to their ability to cause skin damage through accidental exposure or deliberate attacks. Lewisite rapidly penetrates the skin, causing inflammation and blistering. This study focuses on developing a cream formulation of a therapeutic agent, called integrated stress response inhibitor (ISRIB), to treat lewisite-induced injuries. Moreover, animal studies demonstrate a molecular target engagement (ISR) and significant efficacy of ISRIB against lewisite-induced cutaneous injury. The goal of this formulation is to enhance the delivery of ISRIB directly to affected skin areas using an oil-in-water cream emulsion system. We investigated various excipients, including oils, surfactants, emollients, and permeation enhancers, to optimize ISRIB's solubility and penetration through the skin. The result of this study indicated that the optimal formulation includes 30 % w/w of N-Methyl-2-pyrrolidone, dimethyl sulfoxide and Azone® at a pH of 5. 5. It delivered the highest amount of ISRIB into the skin, demonstrating highest skin absorption with no detectable systemic exposure. Additionally, characterization of the cream, including texture analysis, emulsion type, and content uniformity, confirmed its' suitability for topical application. These findings suggest that ISRIB cream formulation is a promising approach for the localized treatment of skin injuries caused by lewisite.

Cocos nucifera and glycerine afterwork moisturizers for secondary prevention of hand dermatitis among fabric worker: a randomized, double-blind, cross over trial.

The use of skin barrier-enhancing topical medication is a favorable approach for the treatment of occupational hand dermatitis (OHD). Cocos nucifera or coconut oil is one of the best sources of lipid enriched with laurate acid, and glycerin is a well-known humectant that improves skin hydration. This study is aimed is to evaluate the effectiveness of C. nucifera and glycerin for secondary prevention of OHD among batik (Indonesian traditional fabric) workers. In a randomized, double-blind, crossover trial, the effect of glycerine-C. nucifera cream versus glycerin-only was considered with multiple afterwork applications of moisturizer over a 2-week period on batik workers with OHD. Assessment of trans-epidermal water loss (TEWL), skin capacitance, and a clinical assessment using the Hand Eczema Severity Index (HECSI) were carried out at day 0 and 14. The results show thirty-two batik dyeing and/or rinsing workers were enrolled in the study with mild to moderate OHD. Clinical improvement was demonstrated by 20% decrease in HECSI and TEWL, and 20% increase in skin capacitance. Both moisturizers were equally effective for the secondary prevention of OHD. As a conclusion, glycerine-C. nucifera and glycerin-only cream are equally effective for secondary prevention for OHD among batik worker to reduce the prevalence of hand dermatitis.

Effects of a pH-Regulating Emollient Cream in Mild Atopic Dermatitis Patients with Moderate Localized Lesions.

INTRODUCTION: Increased skin pH values in patients with atopic dermatitis (AD) contribute to poor antimicrobial and permeability barrier functions of the skin. In practice, the majority of topical preparations available for dry skin conditions do not provide sufficient pH and buffering capacity for maintaining optimum skin surface conditions. To address this issue, we tested a novel zinc lactobionate preparation to determine whether the regular application would lower skin surface pH, and in doing so improve the condition of lesional skin. METHODS: The assessment for local severity of AD was done with the Scoring Atopic Dermatitis Index (SCORAD) and skin dryness was assessed by capacitance measurement. RESULTS: The results showed that the test product lowered skin pH and improved AD skin lesions from moderate to mild during 2 weeks of application. In the treated area a lowered pH of about 0.85 units was found. Together with the lowering of pH, the local SCORAD significantly improved from 8.3 on average down to 4.0, while in the untreated area, only a slight improvement (from 8.2 to 6.4) was found. CONCLUSION: Synergistic effects of the test product's pH lowering and emollient properties might explain the observed improvements in clinical signs of AD and further research against a comparator would allow the specific contribution of pH modulation to these improvements to be unambiguously isolated.

Clinical Evaluation of the Efficacy of Itch-Relief Moisturizers Containing Maltotetraose for Dry, Itchy, and Sensitive Skin.

Itching is a prominent clinical manifestation of sensitive skin; it reduces cutaneous barrier function, mainly caused by dryness. Scratching to relieve itching destroys the skin barrier, thus forming the itch-scratch cycle that results in additional disruption of skin barrier and chronic itching. Treatment involves alleviation from itching for sensitive skin. Recently, substance P (11-amino acid neuropeptide of the tachykinin family) and neurokinin 1 receptor (NK1R) have been considered to provide a key pathway to treat chronic itching. A single-center, open-label study was conducted comprising subjects with dry, itchy, and sensitive skin to evaluate the efficacy of two types of itch-relief moisturizers, mist and lotion, containing maltotetraose (MTO). In all, 35 subjects used mist containing MTO, resulting in significant improvement in itch score from 1 minute to 2 hours following single application. On the other hand, 34 subjects applied lotion containing MTO for 1 week, resulting in significant improvement in itch score, skin hydration, and clinical scores of erythema/redness and dryness; however, in both cases, improve-ment was not observed in the measurement of transepidermal water loss (TEWL). It was concluded that two types of itch-relief moisturizers containing MTO were effective for dry, itchy, and sensitive skin.

Spray skin protectant versus standard moisturiser in the prevention of radiodermatitis in patients with anal canal and rectal cancer: A randomised clinical trial.

The evidence on products for the prevention of radiodermatitis is limited. The primary objective was to analyse the effectiveness of the spray skin protectant 'non-burning barrier film' in the prevention of radiodermatitis with moist desquamation in patients with the anal canal and rectal cancer followed in nursing consultations compared to a standardised moisturiser based on Calendula officinalis and Aloe barbadensis. Single-blind randomised clinical trial. The study was performed in a hospital in Rio de Janeiro, Brazil, with 63 patients undergoing anal canal and rectal cancer treatment, randomised into one of the following two groups: an experimental group, which used a spray skin protectant and a control group, which used a moisturiser. Data were collected using an initial and subsequent evaluation form and were assessed using descriptive and inferential analyses. Participants who used the spray skin protectant had a lower chance of presenting radiodermatitis with moist desquamation and a longer time without this outcome when compared to the control group. The overall incidence of radiodermatitis was 100%, with 36.5% being severe. Furthermore, 17.5% of participants discontinued radiotherapy due to radiodermatitis. There were no differences between the groups regarding the severity of radiodermatitis and the number of patients who discontinued radiotherapy. The skin protectant was effective in preventing radiodermatitis with moist desquamation amongst patients with anal canal and rectal cancer.

Infection in preterm infants receiving topical emollient oil massage: a systematic review and meta-analysis of randomised control trials.

BACKGROUND: Preterm infants are highly susceptible to infections, which significantly contribute to morbidity and mortality. This systematic review and meta-analysis investigated the effectiveness of topical emollient oil application in preventing infections among preterm infants. METHODS: A comprehensive search was conducted across multiple electronic databases (PubMed, Cochrane, Scopus, Clinical trials, Epistemonikos, HINARI and Global Index Medicus) and other sources. A total of 2185 articles were identified and screened for eligibility. The quality of included studies was assessed using the Cochrane Risk of Bias Tool for randomised controlled trials. Data analysis was performed using StataCrop MP V.17 software. Heterogeneity among the studies was evaluated using the I2 and Cochrane Q test statistics. Sensitivity and subgroup analyses were conducted. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist guided the presentation of the results. RESULTS: Of 2185 retrieved articles from initial searches, 11 met eligibility criteria and were included in the final analysis. A random effects meta-analysis revealed that infants who received massages with emollient oils had a 21% reduced risk of infection (risk ratio=0.79, 95% CI 0.64 to 0.97, I2=0.00%). Subgroup analyses indicated that preterm babies who received topical emollient oil massages with coconut oil, administered twice a day for more than 2 weeks, had a lower likelihood of acquiring an infection compared with their non-massaged counterparts. CONCLUSION: It is quite evident from this analysis that topical emollient oil application in preterm neonates is most likely effective in preventing infection. However, further studies, particularly from the African continent, are warranted to support universal recommendations.

Alternatives to Conventional Topical Dosage Forms for Targeted Skin Penetration of Diclofenac Sodium.

Skin penetration of an active pharmaceutical ingredient is key to developing topical drugs. This penetration can be adjusted for greater efficacy and/or safety through the selection of dosage form. Two emerging dosage forms, cream-gel and gel-in-oil emulsion, were tested for their ability to deliver diclofenac into the skin, with the target of maximising skin retention while limiting systemic exposure. Prototypes with varying amounts of solvents and emollients were formulated and evaluated by in vitro penetration testing on human skin. Cream-gel formulas showed better skin penetration than the emulgel benchmark drug even without added solvent, while gel-in-oil emulsions resulted in reduced diffusion of the active into the receptor fluid. Adding propylene glycol and diethylene glycol monoethyl ether as penetration enhancers resulted in different diclofenac penetration profiles depending on the dosage form and whether they were added to the disperse or continuous phase. Rheological characterisation of the prototypes revealed similar profiles of cream-gel and emulgel benchmark, whereas gel-in-oil emulsion demonstrated flow characteristics suitable for massaging product into the skin. This study underlined the potential of cream-gel and gel-in-oil emulsions for adjusting active penetration into the skin, broadening the range of choices available to topical formulation scientists.

Effectiveness of topical hyaluronic acid of different molecular weights in xerosis cutis treatment in elderly: a double-blind, randomized controlled trial.

Dry skin is a common dermatological condition that frequently affects the elderly. A contributing cause to dry skin is a reduced concentration of hyaluronic acid (HA) in both the epidermis and dermis. The effectiveness of moisturizer containing HA as a therapy for dry skin is impacted by its specific molecular weight. Low molecular weight HA (LMWHA) is believed to be more effective in replenishing skin hydration in aging skin compared to High Molecular Weight HA (HMWHA) due to its ability to penetrate the stratum corneum. However, there is a lack of clinical research supporting this claim. A double-blind, randomized controlled trial was conducted on 36 residents of a nursing home in Jakarta. The participants, aged between 60 and 80 years, had been diagnosed with dry skin. Each test subject was administered three distinct, randomized moisturizing lotions (LMWHA, HMWHA, or vehicle), to be topically applied to three separate sites on the leg. Skin capacitance (SCap), transepidermal water loss (TEWL), and specified symptom sum score (SRRC) were measured at weeks 0, 2, and 4. After four weeks of therapy, area that was treated with LMWHA showed greater SCap values compared to the area treated with HMWHA (56.37 AU vs. 52.37 AU, p = 0.004) and vehicle (56.37 AU vs. 49.01 AU, p < 0.001). All groups did not show any significant differences in TEWL and SRRC scores. No side effects were found in all groups. The application of a moisturizer containing LMWHA to the dry skin of elderly resulted in significant improvements in skin hydration compared to moisturizers containing HMWHA and vehicle. Furthermore, these moisturizers demonstrated similar safety in treating dry skin in the elderly. ClinicalTrials.gov Identifier NCT06178367, https://clinicaltrials.gov/study/NCT06178367 .

Going Beyond Ceramides in Moisturizers: The Role of Natural Moisturizing Factors.

Xerosis is experienced by almost everyone at some time in their lives and the foundation of management of dry skin (both consumer- and healthcare professional--directed) rests on the use of moisturizers. Given the wide range of available moisturizers, counseling patients about selecting the optimum moisturizer for their individual situation relies on knowledge of ingredients and formulations. Traditionally, the main focus for many moisturizers centered on the core functional and structural role of ceramides within the epidermal barrier.  However, while a key aspect of transepidermal water loss and other skin barrier functions, components other than ceramides are equally essential in increasing moisturization. The skin's natural moisturizing factors (NMFs) are a complex mixture of water-attracting compounds such as amino acids, urea, lactate, pyrrolidone carboxylic acid (PCA), and electrolytes which play a fundamental role in preserving physiologic function by regulating the water content of the stratum corneum. By facilitating water retention, NMFs contribute significantly to the suppleness, elasticity, normal desquamation, and overall integrity of the skin barrier. Incorporation of NMFs into moisturizers addresses critical deficiencies in the skin's moisture balance that exist in xerotic and atopic skin, and in many skin disorders, mitigating signs and symptoms associated with xerosis and promoting optimal skin health. The biochemical composition of NMFs and the intricate interplay with epidermal homeostasis translate to a central role in moisturizers used for prophylactic and therapeutic management of various dry skin conditions, beyond ceramides alone. J Drugs Dermatol. 2024;23(6):466-471.     doi:10.36849/JDD.8358.

Heatmap Evaluation of Facial Hydration Using a Novel Python Program.

BACKGROUND: Evaluating cleansers and moisturizers provides important information to guide clinicians in the recommendation of these products. This project was performed to visualize skin hydration via heatmap after the use of a gentle skin cleanser (GSC) and moisturizing lotion (ML). METHODS: Half-face, intra-individual open-label study in healthy volunteers. Cleanser was administered in a single application that was then wiped off the face. Moisturizing lotion was applied at least once-daily for one week. Hydration measurements were made at 30 pre-defined points on half of the face, at baseline, and 30 minutes post-application; an additional assessment at week 1 was made for the moisturizing lotion. Heatmaps were generated using Python programming software to interpolate hydration values to colors that were then superimposed onto the volunteer's facial image.  Results: Five subjects completed the cleanser assessments, and 5 subjects completed the 30-minute evaluation for the lotion, with 4 completing the week 1 assessment. There was a visible shift in skin hydration post-GSC application from values approximately in the 12-42 AU (arbitrary unit) range to 30-60 AU at 30 minutes. Similarly, there was a shift in hydration from baseline to 30 minutes that continued to increase through week 1 of ML use. CONCLUSIONS: This innovative heatmap data generation showed a clear, visual change in hydration over time. There was a visible shift in hydration values from baseline to 30 minutes after application of cleanser; hydration also improved after use of moisturizing lotion at 30 minutes and increased after week 1 application.  J Drugs Dermatol. 2024;23(6):463-465.     doi:10.36849/JDD.8221.

Effect of topical emollient oil application on weight of preterm newborns: A systematic review and meta-analysis.

BACKGROUND: Synthesizing current evidence on interventions to improve survival outcomes in preterm infants is crucial for informing programs and policies. The objective of this study is to investigate the impact of topical emollient oil application on the weight of preterm infants. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted. To identify relevant studies, comprehensive searches were conducted across multiple databases, including PubMed, Cochrane, Scopus, Clinical trials, ProQuest Central, Epistemonikos, and gray literature sources. The inclusion criteria were based on the PICO (Population, Intervention, Comparison, and Outcomes) format. Study quality was assessed using the Cochrane risk of bias tool for randomized trials (RoB 2.0). Data analysis was performed using StataCrop MP V.17 software, which included evaluating heterogeneity, conducting subgroup analysis, sensitivity analysis, and meta-regression. The findings were reported in accordance with the PRISMA checklist, and the review was registered with PROSPERO (CRD42023413770). RESULTS: Out of the initial pool of 2734 articles, a total of 18 studies involving 1454 preterm neonates were included in the final analysis. Fourteen of these studies provided data that contributed to the calculation of the pooled difference in mean weight gain in preterm neonates. The random effects meta-analysis revealed a significant pooled difference in mean weight gain of 52.15 grams (95% CI: 45.96, 58.35), albeit with high heterogeneity (I2 > 93.24%, p 0.000). Subgroup analyses were conducted, revealing that preterm infants who received massages three times daily with either sunflower oil or coconut oil exhibited greater mean differences in weight gain. Meta-regression analysis indicated that the type of emollient oil, duration of therapy, and frequency of application significantly contributed to the observed heterogeneity. A sensitivity analysis was performed, excluding two outlier studies, resulting in a pooled mean weight difference of 78.57grams (95% CI: 52.46, 104.68). Among the nine studies that reported adverse events, only two mentioned occurrences of rash and accidental slippage in the intervention groups. CONCLUSION: The available evidence suggests that the application of topical emollient oil in preterm neonates is likely to be effective in promoting weight gain, with a moderate-to-high level of certainty. Based on these findings, it is recommended that local policymakers and health planners prioritize the routine use of emollient oils in newborn care for preterm infants. By incorporating emollient oils into standard care protocols, healthcare providers can provide additional support to promote optimal growth and development in preterm infants.

Skin-centered strategies in food allergy prevention.

While the early introduction of food allergens in the infant diet has been shown to be effective at preventing the development of food allergy (FA), its implementation in real life has been associated with various challenges. Interventions aimed at correcting skin barrier dysfunction have been explored in recent decades as a distinct or complementary mean to prevent allergic sensitization through the skin and subsequent development of FA. Studies assessing the application of emollient from birth have yielded conflicting results, and meta-analyses have demonstrated either no effect or only a slight positive effect on FA prevention. However, a careful review of the clinical trials reveals that different emollients were used, which may have explained some of the discrepancies between study results. Emollient application protocols also varied widely between studies. While firm conclusions cannot be drawn with regard to their overall efficacy at preventing FA, the available data provide valuable insight into the characteristics that could be associated with a more effective intervention. Namely, successful trials tended to use emollients with an acidic pH of 5.5, applied over the entire body, and combined with topical corticosteroids in affected areas. Consensus on the optimal strategy to restore skin barrier function could help improve the homogeneity and clinical relevance of future trials on this topic. In the meantime, clinicians should avoid products associated with worse outcomes.

Atopic Dermatitis.

Atopic dermatitis (AD) is a common, chronic relapsing, and remitting inflammatory skin disease that is characterized by erythematous, scaly, and pruritic lesions often located over the flexural surfaces. Treatment goals of AD include the reduction of itching and burning, as well as the reduction of skin changes. Treatment of AD includes emollients and skin care, topical therapies including topical corticosteroids and steroid-sparing therapies, systemic therapies, and phototherapy.

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

BACKGROUND: 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. OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Atopic dermatitis (AD) affects approximately 20% of children in industrialized countries. AD causes dry, itchy skin and can increase the chance of infections. This study was a substudy of the large Scandinavian PreventADALL trial, including 2394 infants, recruited from the general population between 2014 and 2016. Children in this trial were allocated randomly to receive either a skin intervention, food intervention, combined intervention, or no intervention. Children were examined at 3, 6 and 12 months of age. The examinations involved an investigation of the skin, to evaluate dry skin and skin barrier function by transepidermal water loss (TEWL) in the outer layers of the skin (higher TEWL suggests decreased skin barrier function). The skin intervention consisted of oil baths at least 4 times per week from 2 weeks of age through 8 months of age, and have previously not been shown to prevent AD by 1 and 3 years of age. We aimed to investigate whether frequent oil baths had any effect on TEWL and dry skin. We found that the skin intervention increased TEWL in the first year of life, especially at 3 months of age. Dry skin was less common in the skin intervention groups compared with the groups with no skin intervention. Infants with mutations in the gene coding for a skin barrier protein, called filaggrin, were associated with increased TEWL; however, in the skin intervention group, TEWL was similar among the infants with or without filaggrin mutations. Our findings suggest that oil baths several times per week from early infancy transiently decreases skin barrier function.