Sensitive skin: closing in on a physiological cause

Anti-Inflammatory Potential and Synergic Activities of Eclipta prostrata (L.) L. Leaf-Derived Ointment Formulation in Combination with the Non-Steroidal Anti-Inflammatory Drug Diclofenac in Suppressing Atopic Dermatitis (AD)

Atopic dermatitis (AD) or eczema is an important inflammatory chronic skin disease that brings many complications in its management and treatment. Although several chemical agents are used for treatment, the search for better anti-inflammatory and antibacterial agents of plant origin has been ongoing, since natural compounds, it is commonly believed, are less dangerous than synthetic ones. Therefore, the present study explored a medicinal plant-Eclipta prostrata (L.) L.-for its anti-inflammatory activity alone and in combination with a non-steroidal anti-inflammatory drug (NSAID), diclofenac. The plant extract was used to make a cream formulation for treating atopic dermatitis and as an antibacterial agent against Staphylococcus aures, the major infectious agent associated with AD. The phytochemical analysis of the E. prostrata extract showed the presence of various phytochemicals, including flavonoids, Tannin, saponin, terpenoids, glycosides, phenol, alkaloids, quinone, and protein. The GC-MS profiling of methanolic E. prostrata extract was performed predicted the presence of twenty important phytochemicals, including 2-[5-(2-Hydroxypropyl) oxolan-2-yl]propanoic acid, dl-Menthol, dodecane, undecane, 4,7-dimethyl-, dodecane, 2,6,10-trimethyl-, decane, 2,3,5,8-tetramethyl-, cholest-5-en-3-ol, (3.alpha.)-, TMS derivative, cyclopropane carboxylic acid, 1-hydroxy-, (2,6-di-t-butyl-4-methylphenyl) ester, alpha.-farnesene, propanoic acid, 2-methyl-, 2-ethyl-1-propyl-1,3-propanediyl ester, diethyl phthalate, corticosterone, 2-methylpropionate, hentriacontan-13-ol, O-TMS, phthalic acid, 2,4-dimethylpent-3-yl dodecyl ester, hexasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11-dodecamethyl-, acetic acid, 4-t-butyl-4-hydroxy-1,5-dimethyl-hex-2-ynyl ester, octadecane, 2-methyl- octacosane, 1-iodo-, nonacosane, and eicosyl isopropyl ether. Using an egg albumin denaturation inhibition assay, the anti-inflammatory activities of E. prostrata alone and in combination with diclofenac were investigated, and they showed 93% and 99% denaturation inhibition at 5 mg concentration of E. prostrata in alone and combination with diclofenac, respectively. Heat-induced haemolysis showed 2.5% and 2.4% of haemolysis at 5 mg of E. prostrata alone and in combination with diclofenac, respectively. An MTT assay performed using L929 cells proved that the extract has no cytotoxic effect. The plant extract displayed potential antibacterial activity against Staphylococcus aureus; the growth was inhibited at 1 mg/mL of E. prostrata extract. Thus, based on this evidence, the authors suggest that E. prostrata extract should be studied further for its anti-inflammatory and antibacterial activities and topical application in the treatment of atopic dermatitis.

Controlled comparison evaluation of the soothing effect of 3 cosmetic products on skin discomfort induced by an irritant chemical agent (capsaicin)

BACKGROUND

Sensitive skin is a highly prevalent problem. The objective of the study was to assess whether the tested products are effective and safe in terms of improving the symptoms of sensitive skin.

METHODS

A clinical randomized split-face study was carried out on 24 healthy female subjects. Three cosmetic combinations were tested versus vehicle: product A (Solía Thermal Spring Water-TSW-from Cantabria, Spain + diatom algae-P. tricornutum-extract), product B (Solía TSW + diatom algae extract + Annona cherimola Fruit Extract) and product C (Solía TSW + diatom algae extract + Annona cherimola Fruit Extract + niacinamide). Prior to each application of the study Product (A, B, or C)/vehicle, 10% of aqueous solution of capsaicin to induce skin irritation was applied, mimicking the symptoms of sensitive skin. Stinging and burning sensations were evaluated at different time points.

RESULTS

All three tested products A, B, and C showed to act better in calming the symptoms induced by capsaicin when compared to the vehicle.

CONCLUSIONS

The tested products would be an interesting option for treating stinging and burning sensations in sensitive skin patients.

Development and validation of a prospective questionnaire for assessing oily sensitive skin

BACKGROUND

Skin type has a strong influence on how sensitive skin develops, with oily skin accounting for a larger proportion of sensitive skin. However, there has not been a scientifically sound questionnaire for determining oily sensitive (OS)-type skin in prior studies.

OBJECTIVES

In order to identify OS-type skin in the general population, we therefore intend to create an OS-type skin evaluation questionnaire, develop various thresholds through data analysis and classify skin based on two dimensions of sensitivity and oiliness.

METHODS

A questionnaire with questions regarding subjects' basic information, skin oiliness and skin sensitivity was given to each individual who participated in the study (n = 1297). To define the thresholds for OS-type skin, receiver-operating characteristic (ROC) curves were generated. The results of the lactic acid stinging test (LAST) and noninvasive instrument information obtained were compared with the thresholds mentioned above to verify the effectiveness of this tool.

RESULTS

According to the ROC curves, questionnaire cut-off values of 11.5, 20.5 and 29.5 can be used to detect mildly, moderately and severely sensitive skin, respectively. In addition, the questionnaire cut-off values of 22.5 and 31.5 can be used to detect moderately and severely oily skin, respectively. According to our study, the four sensitive-skin groups' LAST scores differed significantly from one another, while the skin sebum levels differed significantly between the three oily groups. Additionally, the EI and LAST scores were significantly correlated with skin sensitivity levels, whereas sebum, moisture and EI were positively correlated with skin oiliness levels.

CONCLUSIONS

We developed an OS-type skin evaluation questionnaire that has been tested and shown scientifically to be a promising method for evaluating OS-type skin and to completely examine the traits of sensitive and oily skin.

The clinical efficacy and tolerability of a novel triple acid exfoliating blend for reducing signs of photoaging in sensitive skin

BACKGROUND

Chemical exfoliation of the skin is a frequently utilized treatment in dermatology to improve the appearance and health of photoaged skin. Photodamaged skin is especially prone to dryness and irritation. Over-exfoliation with at-home products are partially to blame for the "epidemic" of sensitive skin affecting over half the population. Combining AHA, BHA, and PHA together creates a complementary blend that has the potential to target numerous age-related changes in the skin including the appearance of pores and smoothing skin texture, while firming skin and increasing its collagen and moisture content.

OBJECTIVES

The following study tested the clinical efficacy of a triple acid blend designed specifically for sensitive skin and measured improvements in signs of photodamage and hydration levels in the skin over time.

METHODS

Thirty females aged 35-60 with mild to moderate facial lines, wrinkles, sun damage, uneven skin tone/texture, dark spots, or pores were enrolled. Subjects were instructed to use the test article, DWB-EN, on a clean face at night 3 times weekly with 48 h between applications for 4 weeks.

RESULTS

Statistically significant improvements were noted in all parameters of photoaging clinical assessments (wrinkles, pores, overall appearance, luminosity, visible texture, skin tone evenness, hyperpigmentation) at the end of the 4-week study period. There were no instances of skin irritation throughout the duration of this study despite half of the women having sensitive skin.

CONCLUSIONS

Overall, this study demonstrated the clinical efficacy and tolerability of DWB-EN for treating photoaging in subjects with all skin types.

Development of a biomarker-based platform for comprehensive skin characterization using minimally invasive skin sampling and quantitative real-time PCR

BACKGROUND

Classifying diverse skin types is crucial for promoting skin health. However, efficiently identifying and analyzing relevant biomarkers from a vast array of available genetic data is challenging. Therefore, this study aimed to develop a precise and efficient platform for analyzing specific skin biomarkers using quantitative real-time PCR (qRT-PCR) with the minimal invasive skin sampling method (MISSM).

MATERIALS AND METHODS

MISSM was used for RNA extraction from skin samples, followed by qRT-PCR analysis to quantify the expression of 20 biomarkers associated with skin characteristics (four biomarkers each for five skin characteristics). Noninvasive measurements from 299 Korean participants were utilized to correlate biomarker expression with skin parameters. Statistical analyses were conducted between biomarker expression levels and noninvasive skin measurements to select the relatively best-performing biomarker for each skin characteristic.

RESULTS

Collagen type 1 alpha 1 (COL1A1) and moesin (MSN) were identified as skin aging biomarkers. Krüppel-like factor 4 (KLF4) and serine peptidase inhibitor Kazal type 5 (SPINK5) were identified as skin dryness biomarkers, whereas melan-A (MLANA) was selected as a biomarker for understanding pigmentation dynamics. Myelin protein zero like 3 (MPZL3) and high mobility group box 2 (HMGB2) were identified as markers of oily skin and skin sensitivity, respectively. Statistically significant correlations were found between the biomarker expression levels and noninvasive skin characteristic measurements.

CONCLUSION

This study successfully developed a platform for the precise evaluation of individual skin characteristics using MISSM and qRT-PCR biomarker analysis. By selecting biomarkers that correlate with noninvasive measurements of skin characteristics, we demonstrated the platform's efficacy in assessing diverse skin conditions.

Does sensitive skin lie in epidermal barrier impairment or abnormalities? Results from an observational study assessing biophysical parameters

BACKGROUND

The pathophysiology of sensitive skin is largely unknown and no univocal data on the role of the epidermal barrier impairment have been identified. The aim of this study was to assess whether subjects with or without sensitive skin differ for some biophysical skin parameters, which reflect skin barrier integrity or skin hyperactivity.

METHODS

This observational, cross-sectional study included adult volunteers not affected with chronic inflammatory skin diseases who attended the Unit of Dermatology and the Center of Cosmetology of the University of Ferrara, Ferrara, Italy, between March 2021 and November 2022. All subjects, subdivided into those with or without sensitive skin, based on either Lactic Acid Stinging Test (LAST) result or a questionnaire-based skin sensitivity score ≥4, were tested for transepidermal water loss (TEWL), skin elasticity and hydrations and dermographism.

RESULTS

One hundred and eighty-seven subjects were included. No significant differences in terms of TEWL, elasticity and hydration levels were recorded between subjects with sensitive skin and those without, subdivided according to both the LAST result and the questionnaire score. Dermographism was elicited more in subjects with sensitive skin than in the others, although without statistical significance.

CONCLUSIONS

The study failed to find significant biophysical differences between sensitive and non-sensitive skin. Therefore, the role of skin barrier impairment does not appear to be a necessary condition in determining an abnormal skin sensitivity to potentially unpleasant and irritating stimuli. These findings indirectly support the relevance of a peripheral sensory neural hyperactivity in the pathophysiology of sensitive skin.

The Protective Effects of Moisturizer Containing Potentilla anserina Extract in the Topical Treatment of Skin Damage Caused by Masks

The use of face masks during the COVID-19 pandemic resulted in significant societal changes, particularly for individuals with sensitive skin. To address this issue, the researchers explored traditional medicine and identified Potentilla anserina extract as a potential solution due to its anti-inflammatory and moisturizing effects. This research investigated how this extract influences skin hydration, barrier function, and itching. The findings revealed that the extract had a hydrating effect by elevating Aquaporin-3 (AQP3) expression. Additionally, the study demonstrated that the extract improved skin barrier function, with Filaggrin (FLG) expression being approximately three times higher (p < 0.001) in the Potentilla-anserina-extract-treated group compared to the control group and the genes associated with itching being reduced. In this process, we researched and developed HPβCD (hydroxypropyl-β-cyclodextrin)-Liposome containing Potentilla anserina extract, gradually and sustainably releasing the active components of the Potentilla anserina extract. During four weeks of clinical trials involving individuals wearing masks for over 6 h a day, a moisturizer containing Potentilla anserina extract demonstrated a notable reduction in skin redness. Hemoglobin values (A.U.), which serve as indicators of skin redness, showed decreases of 5.06% and 6.74% in the test area inside the mask after 2 and 4 weeks, respectively, compared to the baseline measurements. Additionally, the moisturizer containing Potentilla anserina extract notably decreased Trans Epidermal Water Loss (TEWL), with reductions of 5.23% and 9.13% observed in the test area inside the mask after 2 and 4 weeks, respectively. The moisturizer, especially in the test area treated with the extract-containing moisturizer, significantly enhanced skin hydration compared to the control group. The Corneometer values (A.U) exhibited notable increases of 11.51% and 15.14% in the test area inside the mask after 2 and 4 weeks, respectively. These discoveries emphasize the potential of Potentilla anserina extract and its utility in tackling skin issues caused by mask wearing, including enhancing moisture, fortifying the skin's barrier, and alleviating itching. These results indicate that moisturizers incorporating specific ingredients provide greater benefits compared to conventional moisturizers.

Analysis of facial redness by comparing VISIA and YLGTD

BACKGROUND

Erythema, characterized by redness of the skin, is a common symptom in various facial skin conditions. Recent advancements in image processing and analysis techniques have led to the development of methods for analyzing and assessing skin texture. This study aimed to investigate the correlation between the parameters of "You Look Good Today" (YLGTD) and VISIA in the detection and assessment of facial redness.

MATERIALS AND METHODS

Thirty female subjects participated in this experiment, undergoing assessments using both YLGTD and VISIA. The subjects were evaluated for facial redness, and the feature count results within the red zone were measured by VISIA. YLGTD analyzed the number and percentage of red zone pixels. The assessments were conducted between [specific dates] in [location].

RESULTS

The results demonstrated a significant positive correlation between the feature count results within the red zone measured by VISIA and the number of red zone pixels. Similarly, YLGTD exhibited a significant positive correlation with the number and percentage of red zone pixels.

CONCLUSION

In conclusion, our findings suggest a correlation between YLGTD and VISIA in the measurement of facial erythema. YLGTD can serve as a portable device for primary screening assessments, offering a convenient and reliable method to evaluate facial redness. This research contributes to the development of non-invasive techniques for assessing and monitoring facial skin conditions, providing valuable insights for dermatological diagnosis and cosmetic testing.

Results from an extended study on the reliability of a questionnaire for the diagnosis of sensitive skin: Confirmations and improvements

OBJECTIVE

A recently proposed self-assessment questionnaire aimed at diagnosing sensitive skin provided promising results in a relatively small population. The main objectives were: (i) to assess the reliability of the aforementioned questionnaire in a larger population and verify the cut-off score previously found to predict skin sensitivity (defined as positivity to LAST, lactic acid stinging test) and (ii) to define a formula that yields the probability of a positive LAST result.

METHODS

Adult volunteers were included in this observational, cross-sectional, extended study. Both LAST-positive subjects, who were considered as having sensitive skin ('patients') and negative ones ('controls') completed the questionnaire, which concerned sensitivity to possible triggers of unpleasant skin sensations in real life. A cumulative score (questionnaire-based skin sensitivity score, 0-10) was calculated from the sum of all items.

RESULTS

Three hundred and sixty-four subjects were enrolled, 214 patients and 150 controls. The mean questionnaire-based skin sensitivity score was significantly higher among patients than controls. Using two different methods, cut-off values of 4 and 5 were defined for the identification of LAST-positive subjects, with 76.6% and 72.8% accuracy, respectively. Scores below 4 or above 5 showed a high (80% or better) negative or positive predictive value, respectively. The coefficients found that in multivariate analysis for each questionnaire item, gender and age allowed us to calculate the probability of LAST positivity with higher precision taking into account the 'relative weight' of each factor.

CONCLUSION

With small variations in the results, the self-assessment questionnaire confirmed its reliability for diagnosing sensitive skin in clinical practice.

Can contagious itch be affected by positive and negative suggestions?

Contagious itch can be evoked by observing people scratching. Verbal suggestions about to-be-received itch can influence itch intensity, as shown by placebo research, but it is unknown whether this extends to contagious itch. The current study aimed to replicate prior findings that listening to scratching and rubbing sounds elicits contagious itch, and to investigate whether suggestions can modulate this process. Healthy participants (n = 140) received positive or negative suggestions about itch in response to the sounds (aimed to decrease or increase expected itch, respectively), or no specific suggestions as a control. Participants listened to a number of audio fragments with scratching and rubbing sounds. The amount of expected itch as well as itch sensation after each audio fragment were measured by self-report. Suggestions had no effect on the expected itch. Both rubbing and scratching sounds significantly elicited itch in all groups. Scratching sounds induced more itch than rubbing sounds exclusively in the control group. These findings indicate that short suggestions might be not effective enough to modify the expectations of people regarding contagious itch. Furthermore, suggestions modulate contagious itch to some degree, but not in the hypothesized direction. Potential similarities and differences in the neurobiological mechanisms of contagious itch and nocebo effects are discussed.

An Autologous Topical Serum Derived from Platelet-Rich Plasma Therapy for the Management of Sensitive Skin Alterations: A Case Series Report

Background

Although the underlying pathophysiology of sensitive skin remains unknown, it presents clinical symptoms like erythema, burning and dryness associated with other inflammatory dermatoses such as dermatitis or rosacea.

Objective

The aim of the present report was to provide preliminary data about the efficacy of Endoret-Serum (ES) as an autologous therapy for the topical management of sensitive skin alterations.

Materials and Methods

Five patients underwent a daily topical ES treatment that was maintained for three months. Clinical assessment was carried out using validated dermatological surveys (DLQI, IGA, Likert, PGI-I). Additionally, skin hydration measurement and high-resolution topographic and reflectance confocal imaging analysis were carried out.

Results

No adverse events were observed during the treatment. At the end of the follow-up period, surveys highlighted a significant therapeutic effect compared to baseline. Skin hydration was also improved, and topographic images showed a decrease in patient’s underlying inflammatory and vascular condition.

Conclusion

This preliminary report suggests that Endoret-Serum may be useful in the management of clinical symptoms derived from sensitive skin alterations.

The effects of wearing a face mask and of subsequent moisturizer use on the characteristics of sensitive skin

Background

COVID‐19 is a serious respiratory disease, and wearing masks has become essential in daily life. Nevertheless, the number of people complaining of skin problems caused by wearing masks is increasing. Therefore, we investigated the characteristics of changes in sensitive skin caused by wearing a mask.

Materials and methods

Twenty healthy Korean women with sensitive skin participated in this study. To determine any skin‐related changes caused by mask‐wearing, we evaluated redness, hydration, transepidermal water loss (TEWL), and moisture at 2.5 mm below the surface before and 4 h after wearing a Korea Filter 94 mask. In addition, we tested whether applying a moisturizer for 30 min after mask removal could reverse any mask‐induced changes.

Results

Skin redness and TEWL were significantly increased at 4 h after wearing a mask (p < 0.05), otherwise skin hydration and the 2.5 mm moisture were significantly decreased (p < 0.05). After applying the moisturizer, skin redness and TEWL were significantly decreased compared to their values 4 h after wearing masks (p < 0.05), whereas skin hydration and the 2.5 mm moisture were significantly increased (p < 0.05). Moreover, after applying the moisturizer, skin redness and TEWL were significantly reduced compared to the pre‐masking baseline (p < 0.05), whereas skin hydration was significantly increased (p < 0.05); the 2.5 mm moisture showed no significant change.

Conclusion

We observed that wearing masks causes physiological changes in sensitive skin, whereas applying a moisturizer after removing the mask improved skin conditions.

Quantifying skin sensitivity caused by mechanical insults: A review

BACKGROUND

Skin sensitivity (SS) is a commonly occurring response to a range of stimuli, including environmental conditions (e.g., sun exposure), chemical irritants (e.g., soaps and cosmetics), and mechanical forces (e.g., while shaving). From both industry and academia, many efforts have been taken to quantify the characteristics of SS in a standardised manner, but the study is hindered by the lack of an objective definition.

METHODS

A review of the scientific literature regarding different parameters attributed to the loss of skin integrity and linked with exhibition of SS was conducted. Articles included were screened for mechanical stimulation of the skin, with objective quantification of tissue responses using biophysical or imaging techniques. Additionally, studies where cohorts of SS and non-SS individuals were reported have been critiqued.

RESULTS

The findings identified that the structure and function of the stratum corneum and its effective barrier properties are closely associated with SS. Thus, an array of skin tissue responses has been selected for characterization of SS due to mechanical stimuli, including: transepidermal water loss, hydration, redness, temperature, and sebum index. Additionally, certain imaging tools allow quantification of the superficial skin layers, providing structural characteristics underlying SS.

CONCLUSION

This review proposes a multimodal approach for identification of SS, providing a means to characterise skin tissue responses objectively. Optical coherence tomography (OCT) has been suggested as a suitable tool for dermatological research with clinical applications. Such an approach would enhance the knowledge underlying the multifactorial nature of SS and aid the development of personalised solutions in medical and consumer devices.

Burden of Sensitive Skin (BoSS) Questionnaire and Current Perception Threshold: Use as Diagnostic Tools for Sensitive Skin Syndrome

The assessment of sensitive skin syndrome, characterized by subjective unpleasant sensations, remains a challenge, since there is no international consensus on the best diagnostic tools. This study evaluated the combination of the Burden of Sensitive Skin (BoSS) questionnaire and the current perception threshold as diagnostic tools for sensitive skin syndrome, and the relationship between BoSS and the subjects’ smoking status, phototype and skin type. A total of 100 women completed the BoSS questionnaire, and current perception threshold was measured on the face. The BoSS score was significantly higher in the self-reported sensitive skin group compared with the non-sensitive skin group (25.61 vs 14.05; p < 0.001), and in non-smokers vs smokers (23.00 vs 18.37; p < 0.05). In addition, the current perception threshold values were similar between the sensitive and non-sensitive groups. These results suggest that BoSS is a better diagnostic tool for sensitive skin syndrome than the current perception threshold, and that smokers less frequently have sensitive skin than do non-smokers.

Proposal of a self-assessment questionnaire for the diagnosis of sensitive skin

Background

Sensitive skin is very common and distressing. Its diagnosis may be difficult with the tools/methods available at the moment.

Aims

To assess the reliability of a self‐assessment questionnaire for the diagnosis of sensitive skin, using the results of lactic acid stinging test (LAST) as a reference for the identification of subjects suffering from this condition. A further objective was to identify the questionnaire cutoff score that better discriminates between subjects with or without sensitive skin.

Patients/methods

Among the adult volunteers included in this observational, cross‐sectional study, both LAST‐positive subjects, who were considered as having sensitive skin (“patients”), and negative ones (“controls”) completed the questionnaire. It consisted of a part for self‐assessing and quantifying (0–10) sensitive skin and another one that included 10 items, each referring to a specific, potentially triggering stimulus. A cumulative score (questionnaire‐based skin sensitivity score, 0–10) was calculated from the sum of all items considered capable of triggering unpleasant skin sensations in real‐life experience.

Results

One hundred and sixty‐two subjects were enrolled, 102 patients and 60 controls; 98 subjects thought they had sensitive skin. The mean questionnaire‐based skin sensitivity score was significantly higher among patients than controls and correlated with skin sensitivity self‐assessments. A cutoff value of 3 was set for the identification of LAST‐positive subjects, with 79% accuracy.

Conclusions

The study self‐assessment questionnaire seems to be a reliable tool for diagnosing sensitive skin in clinical practice. These results led us to identify a numerical cutoff for detecting propensity to experience sensitive skin.

A Survey to Identify Determinants That Influence Self-Perceived Sensitive Skin in a British Population: Clues to Developing a Reliable Screening Tool for Sensitive Skin

Background

Skin sensitivity characteristics and triggers have been identified in populations in previous studies. However, few have compared these characteristics among self-reported sensitive skin.

Objective

The aim of the study was to evaluate and compare specific intrinsic and extrinsic triggers of skin sensitivity between individuals with self-reported sensitive skin and non-sensitive skin.

Methods

A systematic literature review was undertaken to identify intrinsic and extrinsic factors associated with sensitive skin. A 167-item survey was developed on the basis of the literature review. The survey was completed online by a sample of adult participants drawn from the general United Kingdom population. Participants also completed sociodemographic and self-reported health questions.

Results

A total of 3050 surveys were completed: 1526 participants with self-reported skin sensitivity and 1524 participants not reporting skin sensitivity. There was a decrease in self-reported skin sensitivity with increasing age (p<0.05), and proportionally more women reported sensitive skin. Smoking also led to a higher frequency of sensitive skin. All signs and symptoms of sensitive skin, such as itch, dryness/flakiness, roughness and flushing/blushing were more commonly reported by those with self-reported sensitive skin. These were frequently reported in association with external factors (cold/windy weather, clothes and fabrics), as well as internal factors such as pre-existing skin conditions and atopy.

Conclusion

The study evaluated self-reported sensitive skin against a non-sensitive skin in order to identify common inherent and external triggers to distinguish between these groups in a large general population study in the United Kingdom. The key symptoms and signs of this syndrome identified in the literature were confirmed to be reported significantly more when compared with those without sensitive skin. However, no correlation or pattern of symptomology could be identified, reinforcing the complexity of this condition. Given the strong differentiation from the non-sensitive group, the results of this research could be utilised for the development of a clinically meaningful screening tool.

Non-invasive evaluation of subjective sensitive skin by transcriptomics using mRNA in skin surface lipids

Sensitive skin is a condition characterized by hypersensitivity to environmental stimuli, and its pathophysiology has not been fully elucidated. Questionnaires based on subjective symptoms, intervention tests, and measuring devices are used to diagnose sensitive skin; however, objective evaluation methods, including biomarkers, remain to be established. This study aimed to investigate the molecular profiles of self-reported sensitive skin, understand its pathophysiology and explore its biomarkers. Here, we analysed RNAs in skin surface lipids (SSL-RNAs), which can be obtained non-invasively by wiping the skin surface with an oil-blotting film, to compare the transcriptome profiles between questionnaire-based "sensitive" (n = 11) and "non-sensitive" (n = 10) skin participants. Exactly 417 differentially expressed genes in SSL-RNAs from individuals with sensitive skin were identified, of which C-C motif chemokine ligand 17 and interferon-γ pathways were elevated, while 50 olfactory receptor (OR) genes were downregulated. The expression of the detectable 101 OR genes was lower in individuals with sensitive skin compared to that in those with non-sensitive skin and was particularly associated with the subjective sensitivity among skin conditions. The receiver operating characteristic (ROC) curve demonstrated that the mean expression levels of OR genes in SSL-RNAs could discriminate subjective skin sensitivity with an area under the ROC curve of 0.836. SSL-RNA profiles suggest a mild inflammatory state in sensitive skin, and overall OR gene expression could be a potential indicator for sensitive skin.

Inflammasome Activation in Pollution-Induced Skin Conditions

SUMMARY

Exposure to air pollutants has been now associated with detrimental effects on a variety of organs, including the heart, lungs, GI tract, and brain. However, recently it has become clear that pollutant exposure can also promote the development/exacerbation of a variety of skin conditions, including premature aging, psoriasis, acne, and atopic dermatitis. Although the molecular mechanisms by which pollutant exposure results in these cutaneous pathological manifestations, it has been noticed that an inflammatory status is a common denominator of all those skin conditions. For this reason, recently, the activation of a cytosolic multiprotein complex involved in inflammatory responses (the inflammasome) that could promote the maturation of proinflammatory cytokines interleukin-1β and interleukin-18 has been hypothesized to play a key role in pollution-induced skin damage. In this review, we summarize and propose the cutaneous inflammasome as a novel target of pollutant exposure and the eventual usage of inflammasome inhibitor as new technologies to counteract pollution-induced skin damage. Possibly, the ability to inhibit the inflammasome activation could prevent cutaneous inflammaging and ameliorate the health and appearance of the skin.

Achillea Species as Sources of Active Phytochemicals for Dermatological and Cosmetic Applications

Achillea spp. is well known for its broad range of applications and long history of use in traditional medicine around the world. Health benefits of Achillea extracts result from the multitude of secondary metabolites identified in the plants from this genus that include flavonoids, phenolic acids, terpenes, guaianolides, phytosterols, fatty acids, and organic acids. The properties of several Achillea extracts meet also the expectations of a vividly developing cosmetic market. An increasing number of studies on the dermatological properties of Achillea spp. are observed in the recent years, with Achillea millefolium L. being the most studied and used representative of the genus. There is strong scientific evidence showing that also other yarrow species might be rich sources of effective cosmetic ingredients, with skin calming and rejuvenating properties, wound healing activity, and anti-inflammatory potential. Several Achillea extracts and isolated compounds were also shown to display significant tyrosinase inhibitory, antioxidant, and antimicrobial properties and thus are interesting candidates for active ingredients of medications and cosmetic products protecting the skin from the harmful impact of environmental stressors. The aim of this review is to collect the current information on the composition and cosmeceutical significance of different Achillea species.

Correlation Between Facial Skin Microbiota and Skin Barriers in a Chinese Female Population with Sensitive Skin

Background and Aim

The association of microbiota changes with sensitive skin remains controversial until now. Although a strong correlation is detected between skin microbiota distribution and biophysical parameters, there is little knowledge on the link between sensitive skin and skin microbiota in Chinese women. This study aimed to unravel the correlation between facial skin microbiota distribution and skin barriers in Chinese women with sensitive skin.

Materials and Methods

In total, 34 volunteers were enrolled, including 24 subjects with sensitive skin (SS group) and 10 subjects with non-sensitive skin (NS group). The cuticle moisture content, transepidermal water loss (TEWL), and facial skin sebum secretion were measured, and the facial skin surface morphology was evaluated. Sensitive skin samples were collected from the facial (SS-F group) and chest skin of subjects in the SS group (SS-C group), while non-sensitive skin samples were collected from the facial skin of subjects in the NS group (NS-F group). All skin samples were subjected to 16S rRNA sequencing.

Results

16S rRNA sequencing detected Actinobacteria, Firmicutes, and Proteobacteria as the three most common microbiota phyla and Propionibacterium, Paracoccus, and Corynebacterium as the three most common microbiota genera, and there were no significant differences in the relative frequency of Actinobacteria, Firmicutes, or Proteobacteria, or Propionibacterium, Paracoccus, or Corynebacterium among the SS-F, SS-C, and NS-F groups (P>0.05). We detected no significant difference in the diversity of bacterial communities among the SS-F, SS-C, and NS-F groups; however, the Shannon’s diversity index was significantly higher in the NS-F group than in the SS-C group. In addition, Spearman correlation analysis showed a correlation between the microbiota genera and skin physiological parameters (P<0.05).

Conclusion

This study preliminarily unravels the skin microbiota of sensitive skin using a high-throughput tool, and there are no microbiota genera with strong associations with skin physiological parameters.

Does sensitive skin represent a skin condition or manifestations of other disorders?

Sensitive skin or cutaneous sensory syndrome is defined as a skin condition that is hypersensitive to stimuli, presented with itching, irritant, erythema, and dryness. However, is it associated with more than impairment of epidermal functions, psychological stress and topical medication or products? We think that it can be a skin condition or manifestation of other cutaneous or extracutaneous disorders. In this paper, we brief relation of sensitive skin syndrome with cutaneous and extracutaneous disorders, clinically, and pathophysiologically.

Evaluation of skin irritation following weathered crude oil exposure in two mouse strains

Petroleum crude oil spills are common and vary in size and scope. Spill response workers throughout the course of remediation are exposed to so-called weathered oil and are known to report diverse health effects, including contact dermatitis. A murine model of repeated exposure to weathered marine crude oil was employed utilizing two strains of mice, C57BL/6 and BALB/c, to investigate the pathology of this irritant and identify the principal hydrocarbon components deposited in skin. Histopathology demonstrated clear signs of irritation in oil-exposed skin from both mouse strains, characterized by prominent epidermal hyperplasia (acanthosis). BALB/c mice exposed to oil demonstrated more pronounced irritation compared with C57BL/6 mice, which was characterized by increased acanthosis as well as increased inflammatory cytokine/chemokine protein expression of IL-1β, IL-6, CXCL10, CCL2, CCL3, CCL4, and CCL11. A gas chromatography/mass spectrometry method was developed for the identification and quantification of 42 aliphatic and EPA priority aromatic hydrocarbons from full thickness skin samples of C57BL/6 and BALB/c mice exposed to oil samples. Aromatic hydrocarbons were not detected in skin; however, aliphatic hydrocarbons in skin tended to accumulate with carbon numbers greater than C16. These preliminary data and observations suggest that weathered crude oil is a skin irritant and this may be related to specific hydrocarbon components, although immune phenotype appears to impact skin response as well.

Structures of the Skin Microbiome and Mycobiome Depending on Skin Sensitivity

Sensitive skin (SS) syndrome is a globally widespread, self-diagnosed discomfort characterized by subjective complaints. Although the skin microbiome is considered important in skin health, the relationship between the skin microbiome and skin sensitivity is still unknown. Here, we aimed to (i) investigate whether the microbiome and mycobiome of SS are distinct from those of non-sensitive skin (NS), and (ii) define the characteristics of the skin microbiome associated with skin sensitivity. A total of 42 Korean women subjects were recruited (SS, n = 23; NS, n = 19) and the microbiome/mycobiome of their right facial cheeks were analyzed. We identified the differential microbiome and mycobiome structures between SS and NS. The mycobiome of SS was more phylogenetically diverse than that of NS. Lactobacillus and Mucor racemosus were more abundant on SS than NS, whereas Malassezia restricta was less abundant. Interestingly, both skin microbiome and mycobiome varied according to the perceived skin sensitivities of the subjects. This study suggests that the skin microbiome and mycobiome are associated with skin sensitivity. Accordingly, it lays the foundation for developing microbiome-based cosmetics or remedies for individuals suffering from SS syndrome.

Online comment-based prediction of cosmetic ingredient's sensory irritation using gradient boosting algorithm

BACKGROUND

The worldwide prevalence of "sensitive skin" group is estimated at being close to 40%. The main trigger for sensitive skin is the misuse of cosmetics products. Majority of the in vitro studies on cosmetic ingredients developed for topical application to the skin are not able to describe sensory irritation, such as stinging, burning, itching, and tingling. Besides, most of the in vivo tests often encounter problems such as limited number of subjects and usage scenarios deviate from reality.

OBJECTIVE

A gradient boosting algorithm is adopted in our context to integrate multisource of information including skin types, sensory response, and cosmetics ingredients to predict sensory irritation.

METHOD

In this study, online comments were preprocessed to construct a multi-dimensional structured data including skin types, sensory response, and cosmetics ingredients. A gradient boosting regression model was developed where sensory response was predicted based on the abovementioned structured input. The predictions were validated by in vivo test and were shown favorably when comparing with the state-of-the-art results from related works.

RESULT

46 007 samples were collected after data cleaning and were used in model developing. Results showed that the model was capable to predict the sensory response of 16 skin types to different ingredients (R = 0.71, P < 10^-10 ). In addition, this model was validated using data from in vivo studies and presented a value of 75% on specificity, 88.9% on sensitivity, and 82.4% on accuracy.

CONCLUSION

Our approach that is based on a variant of the gradient boosting algorithm provided an adequate solution for understanding the sensory irritation of cosmetic ingredients.

The Prevalence of Sensitive Skin

Sensitive skin has been described as unpleasant sensory responses to stimuli that should not provoke such sensations. Objectively measurable signs of irritation are not always present in individuals with sensitive skin, however, subjective sensory effects such as, itching, burning, stinging, tightness, and dryness, are consistently present. Given the subjective nature of the phenomenon known as sensitive skin, surveys have been a popular approach to evaluating the prevalence of this condition among the general population, and a number of them have been conducted worldwide. Overall, ~60–70% of women and 50–60% of men report having some degree of sensitive skin. However, there are differences between populations in various geographies, and perceptions of sensitive skin at specific anatomic sites. This article is a review of survey data on the prevalence of self-declared sensitive skin in various geographies, among different gender and age groups, and at various anatomic sites. In addition, we review the factors that may contribute to sensitive skin, and the physiological characteristics associated with this condition, including impaired barrier function and heightened neural reactions.

Development and validation of a new tool to assess the Burden of Sensitive Skin (BoSS)

BACKGROUND

Sensitive skin usually manifests itself as unpleasant sensations and sometimes erythema. There are various triggering factors for this condition. Although sensitive skin may alter quality of life, its burden has not yet been explored.

OBJECTIVE

The aim of this study was to develop and validate a specific sensitive skin burden questionnaire called the BoSS (Burden of Sensitive Skin).

METHODS

A conceptual phase was developed, followed by a development phase, external validation, psychometric analysis, test-retest analysis and, finally, a translation, cross-cultural adaptation and cognitive debriefing.

RESULTS

A total of 6471 individuals participated in the study (4614 people in the validation study). The dimensionality of items was evaluated using factor analyses, suggesting three dimensions (self-care, daily life and appearance). Unidimensionality was confirmed by higher order factor analysis. The overall Cronbach's α coefficient was high, and intradimensional coherences all demonstrated good reliability. The final instrument consisted of 14 items. The test-retest reliability demonstrated very good reproducibility. The intraclass correlation of each dimension was high. External validity was confirmed by the correlation coefficients of the BoSS vs. those of the SF-12 and the DLQI assessment tools.

CONCLUSION

BoSS is the first reliable tool to assess the burden of sensitive skin.

Sensitive scalp is associated with excessive sebum and perturbed microbiome

BACKGROUND

Sensitive scalp, one of the most frequent complaints among sensitive skin syndrome, has been described as abnormal and unpleasant sensory reactions of the scalp to environmental stimulus. However, the symptoms are usually objective and hard to diagnose.

OBJECTIVE

This study aimed to reveal the biophysical properties and etiology of sensitive scalp.

METHODS

Sixty-two healthy female subjects were enrolled and divided into nonsensitive scalp (NS) and sensitive scalp (SS) groups according to questionnaires. Noninvasive instruments were used to measure biophysical properties. Ultra-performance liquid chromatography-tandem mass spectrometry and gas chromatography mass spectrometry were introduced to quantify skin lipids profiles, and 16S rRNA sequencing was used to detect the composition of bacteria.

RESULTS

Sensitive scalp showed elevated pH level, more irritated skin, and more fluorescence of porphyrins. Increased sebum production was found in SS group at occiput, among which free fatty acids, cholesteryl ester, and squalene were significantly in higher amount compared with NS. SS also had significantly higher percentage of Propionibacterium, and lower bacterial diversity.

CONCLUSIONS

Taken together, sensitive scalp showed disrupted barrier function, abnormal sebum amount and composition, as well as perturbed microbiome, which might be the direct cause. Products targeting these features could be helpful for the treatment of sensitive scalp.

Sensitive skin in France: a study on prevalence, relationship with age and skin type and impact on quality of life

BACKGROUND

Many epidemiological studies have been performed, but a potential increase in the prevalence of sensitive skin, its relationship with age and skin type and the impact of sensitive skin on quality of life are still debated.

OBJECTIVE

To answer these unresolved questions.

METHODS

An opinion poll was conducted on a representative French 5000 person sample.

RESULTS

Fifty-nine per cent of the people declared very sensitive or fairly sensitive skin (together: sensitive skin), and women (66%) declared sensitive skin more frequently than men (51.9%). The results also showed that sensitive skin is more common (more than 60%) in younger people (<35 years old), and there was a decrease in the following age groups. The univariate analysis demonstrated that sensitive skin was more likely to be reported by people with fair skin (OR = 1.83) and by people with an atopic predisposition (OR = 2.51). The risk of sensitive skin is higher for people with dry skin (OR = 6.18 compared with normal skin), but sensitive skin can occur in other skin types (OR = 2.45 for mixed skin and OR = 2.16 for greasy skin). Quality of life was clearly altered in patients with sensitive skin, as assessed by SF-12 and DLQI.

CONCLUSION

This large study demonstrates that sensitive skin can alter quality of life and is more common in young people and in women as well as patients with dry skin or fair skin or an atopic predisposition. It also suggests that there is an increase in the prevalence of sensitive skin.

Fatty acid supplements improve hair coat condition in rhesus macaques

As captive rhesus macaques often exhibit hair loss, alopecia was quantified and behavior was recorded before, during, and after fatty acid supplementation in six macaques. Fatty acid treatment was associated with a decrease in alopecia and in self-grooming behavior. Therefore, fatty acids may be a viable treatment for alopecia in some captive primates.

A comparison of the effect of certain inorganic salts on suppression acute skin irritation by human biometric assay: A randomized, double-blind clinical trial

Background:

Strontium, zinc, and potassium salts have been demonstrated to inhibit irritation and inflammation when applied topically. Particularly, strontium chloride (SC) and potassium nitrate (KN) are reported to reduce skin and tooth sensitivity. The aim of the present study was to compare the anti-irritant effects of four inorganic salts and assign the ingredient which can suppress skin irritation due to chemical or environmental exposure, more effectively. We compared the anti-inflammatory effects of SC, strontium nitrate (SN), KN, and zinc chloride (ZC).

Materials and Methods:

This double-blind trial was conducted on 32 healthy volunteers with sensitive skin. Irritation was induced by 24 h exposure with 1.0% sodium lauryl sulfate on arms. Treatments were applied by an ointment of SN, SC hexahydrate, KN, and ZC and their 1%, 3%, and 5% (w/v) concentrations were prepared. The dosage was twice daily for 6 days to the irritated areas. Skin reactions were evaluated instrumentally.

Results:

SC had a beneficial effect that was significant overall. All other treatments exert a protective effect in skin barrier function but not significantly. With the exception of ZC, all test substances improved skin hydration but the effect of SC was significant. In respect of colorimetric assessment, all treatments, excluding ZC, reduced erythema significantly compared with an untreated control 7 days after treatment start. There was no support for a dose-response effect.

Conclusion:

Analysis of the biometric measurements revealed that the strontium salts are best, not treating is worst, and there is little difference between the other treatments. Hence, the skin care products containing SC and SN may reduce the signs and symptoms of irritant contact dermatitis.

Sensitive skin

Sensitive skin is a clinical condition defined by the self-reported facial presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus. Sensitive skin may occur in individuals with normal skin, with skin barrier disturbance, or as a part of the symptoms associated with facial dermatoses such as rosacea, atopic dermatitis and psoriasis. Although experimental studies are still pending, the symptoms of sensitive skin suggest the involvement of cutaneous nerve fibres and neuronal, as well as epidermal, thermochannels. Many individuals with sensitive skin report worsening symptoms due to environmental factors. It is thought that this might be attributed to the thermochannel TRPV1, as it typically responds to exogenous, endogenous, physical and chemical stimuli. Barrier disruptions and immune mechanisms may also be involved. This review summarizes current knowledge on the epidemiology, potential mechanisms, clinics and therapy of sensitive skin.

Skin compatibility and efficacy of a cosmetic skin care regimen with licochalcone A and 4-t-butylcyclohexanol in patients with rosacea subtype I

BACKGROUND

Patients with rosacea often show facial sensitivity to cosmetics or skin care products that can influence the severity of symptoms and exacerbate erythema and inflammation. Nevertheless, special skin care is necessary to address cosmetic concerns and reduce the potential side-effects of topical or oral treatment of the disease. Appropriate skin care should comprise gentle cleansing, effective moisturization, soothing actives, UV protection and concealing pigments to help neutralize the appearance of redness.

OBJECTIVE

To determine the compatibility and efficacy of a skin care regimen (consisting of a cleanser, a day care with SPF25 and a night care) containing licochalcone A (Lic A), an anti-irritant from the licorice plant Glycyrrhiza inflata, and 4-t-butylcyclohexanol (SymSitive(®) ), a substance which acts as a sensitivity regulator, in female subjects with clinically determined subtype I rosacea.

METHODS

Thirty-two test subjects with mild to moderate rosacea used the skin care regimen daily for 8 weeks. Clinical assessment of erythema, subjective irritation and clinical photography were performed at baseline and after 4 and 8 weeks. Additionally, a quality-of-life questionnaire was filled out by the test subjects at baseline and week 8. The subjects completed a self-assessment questionnaire on product properties after 4 and 8 weeks of product use.

RESULTS

Clinical assessments and subject response confirmed very good tolerability of the regimen, a statistically significant improvement in clinical grading for erythema and tactile roughness at weeks 4 and 8 and on telangiectasia at week 8 when compared to baseline scores. A statistically significant improvement in facial redness (a*) values, based on the L*a*b* colorimetric system, was determined at week 4 and 8 in comparison to baseline. No difference in corneometric measurement was detected at week 4 and 8 compared to baseline.

CONCLUSION

The skin care regimen was found to be highly compatible with the sensitive facial skin of patients with rosacea subtype I and effective in improving signs of rosacea. Therefore, the daily use of skin care products containing LicA and SymSitive(®) in patients with rosacea improves the overall skin appearance and the quality of life of these patients.

A model for perception-based identification of sensitive skin

BACKGROUND

With high prevalence of sensitive skin (SS), lack of strong evidence on pathomechanisms, consensus on associated symptoms, proof of existence of 'general' SS and tools to recruit subjects, this topic attracts increasing attention of research.

OBJECTIVE

To create a model for selecting subjects in studies on SS by identifying a complete set of self-reported SS characteristics and factors discriminatively describing it.

METHODS

A survey (n = 3058) was conducted, comprising questions regarding socio-demographics, atopy, skin characteristics, personal care, degree of self-assessed SS and subjective and objective reactions to endogenous and exogenous factors. Exploratory factor analysis on 481 questionnaires was performed to identify underlying dimensions and multivariate logistic regression to find contributing variables to the likelihood of reporting SS.

RESULTS

The prevalence of SS was found to be 41%, and 56% of SS subjects reports a concomitant atopic condition. The most discriminative were the eliciting factors toiletries and emotions, and not specific skin symptoms in general.

CONCLUSION

Triggers of different origins seem to elicit SS, it is not defined by concomitant skin diseases only, suggesting existence of 'general' SS. A multifactorial questionnaire could be a better diagnostic than a one-dimensional provocative test.

Evaluation of the severity and triggering factors of sensitive scalp in Chinese females

BACKGROUND

Sensitive scalp which has been recently proposed and assessed by several questionnaires is one of the most cosmetic concerns in sensitive skin syndrome by consumers.

OBJECTIVE

This study is to investigate the prevalence and factors related to the scalp sensitivity in China.

METHODS

Two well-known questionnaires including four-grade self-assessment and 3S, and a new questionnaire we proposed (10Q), were used to evaluate the severity and symptoms of sensitive scalp.

RESULTS

The proportions of sensitive scalp according to self-assessment and 3S were 35.77% and 57.45%, respectively. Distributions of severity and tendency of proportion along ages were significantly different between the two methods. The 10Q questionnaire which we designed could discriminate different grade of severity of sensitive scalp with superior reliability. Moreover, triggering factors which have significant impacts on the symptoms of sensitive scalp were elucidated by logistic regression analysis, including air dryness, exercises, humidity, heat, and sun.

CONCLUSION

Questionnaires with more dimensions and details such as 10Q and 3S should be used for the diagnosis, prognosis, and treatment monitoring on sensitive scalp in Chinese female.

Relationship between transient receptor potential vanilloid-1 expression and the intensity of sensitive skin symptoms

BACKGROUND

Sensitive skin (SS) is a hyper-reactive condition of the skin secondary to external factors, without objective signs of lesion. Its pathogenesis is still under investigation. Transient receptor potential vanilloid-1 (TRPV1) is a cation channel that responds to low pH and is related to nociception, neurogenic inflammation, and pruritus.

AIMS

To determine the expression of TRPV1 in subjects with SS and correlate it with the degree of symptoms and skin pigmentation.

PATIENTS/METHODS

We included 31 subjects self-diagnosed as having SS. Colorimetric values were obtained for assessment of skin phototype, and the lactic acid stinging test (LAST) was performed. Two skin biopsies from the nasolabial fold of each volunteer were obtained. Qualitative analysis of TRPV1 was carried out with immunohistochemistry. Quantitative analysis of TRPV1 was carried out with qRT-PCR.

RESULTS

LAST was positive in 74% of the subjects, 56% of those having tan and brown skin. Immunohistochemistry staining for TRPV1 was greater in positive subjects (P = 0.03), but showed no correlation with the intensity of symptoms. Positive subjects also had higher TRPV1 mRNA expression compared to negative subjects (P < 0.001). This expression showed a positive correlation with the intensity of referred symptoms (R = 0.75, P < 0.001) and skin pigmentation (R = 0.63, P < 0.001).

CONCLUSIONS

TRPV1 expression is upregulated in subjects with sensitive skin, and it correlates with the intensity of the symptoms. Our findings suggest a role for this receptor in the pathogenesis of sensitive skin syndrome.

Evaluation of a topical treatment for the relief of sensitive skin

Background

Approximately, 50% of the population claim to have sensitive skin, which has created an important challenge for dermatologists and the cosmetic industry. This study evaluates the properties of QV Face Rescue Gel (Rescue Gel) that contains a combination of moisturizing and anti-irritant ingredients, and which is used to relieve the symptoms of sensitive facial skin.

Methods

The ability of Rescue Gel to induce collagen types I and III in cultured neonatal human foreskin fibroblasts compared to transforming growth factor beta 1, a known potent inducer of collagen types I and III, was measured using immunofluorescence staining. Furthermore, healthy volunteers were recruited to measure the potential for Rescue Gel to reduce erythema induced by solar-simulated ultraviolet radiation on the skin compared to 0.5% hydrocortisone cream (positive control) as well as it’s ability to decrease transepidermal water loss compared to baseline levels. In addition, the formulation was tested for its potential to be 1) nonstinging using a facial sting/discomfort assay performed on volunteers who reacted positively to lactic acid, 2) nonirritating as determined by repeat insult patch tests, and 3) noncomedogenic.

Results

Rescue Gel significantly induced collagen types I and III in cultured human foreskin fibroblasts similarly to transforming growth factor beta 1. In volunteers, Rescue Gel was shown to significantly reduce erythema induced by solar-simulated ultraviolet radiation similarly to 0.5% hydrocortisone, and to significantly reduce transepidermal water loss compared to baseline levels. Further, the formulation was found to be nonstinging, nonirritating, and noncomedogenic. No adverse events were observed.

Conclusion

In this study, Rescue Gel has been shown to exhibit properties that make it effective for use on sensitive or irritated facial skin, without exacerbation of the symptoms associated with sensitive skin.