The prevalence of self‐declared sensitive skin: a systematic review and meta‐analysis

Study of the soothing effects of troxerutin in alleviating skin sensitivity

BACKGROUND

Transient receptor potential vanilloid 1 (TRPV1) is associated with skin sensitivity and mainly activated by capsaicin and heat. Interestingly, troxerutin can inhibit TRPV1 activation. However, its efficacy in reducing skin sensitivity remains undetermined.

AIMS

We evaluated the efficacy of troxerutin in alleviating skin sensitivity using clinical tests and in vitro experiments.

METHODS

For the in vitro experiment, HaCaT keratinocytes were pretreated with different concentrations of troxerutin, followed by incubation with 50 μM capsaicin for 1, 24, or 48 h. The gene and protein expressions of four inflammatory cytokines involved in skin irritation were determined. Among 35 Korean women with sensitive skin recruited for the clinical trial, 13 were involved in assessing the immediate soothing effects of 0.1% and 0.0095% troxerutin following capsaicin irritation, whereas 22 participated in evaluating the preventive soothing effect of 10% and 1% troxerutin over 4 weeks against capsaicin- and heat-induced irritation. We evaluated the soothing rate using skin redness, visual analog scale, and high temperature sensitive index as evaluation indices.

RESULTS

Troxerutin inhibited the mRNA and protein expressions of cytokines in capsaicin-treated keratinocytes. In the clinical study, 0.1% and 0.0095% troxerutin promptly alleviated capsaicin-induced skin redness, whereas 10% troxerutin notably decreased both the visual analog scale and high temperature sensitive index for capsaicin- and heat-related irritation. However, 1% troxerutin was only effective in reducing the visual analog scale in response to capsaicin irritation.

CONCLUSIONS

Troxerutin can inhibit TRPV1 activation in clinical and in vitro tests.

A randomized controlled double-blinded split-face prospective clinical trial to assess the efficacy, safety, and tolerability of a novel 3-step routine compared to benzoyl peroxide for the treatment of mild to moderate acne vulgaris

Adult acne vulgaris affects up to 43-51% of individuals. While there are numerous treatment options for acne including topical, oral, and energy-based approaches, benzoyl peroxide (BPO) is a popular over the counter (OTC) treatment. Although BPO monotherapy has a long history of efficacy and safety, it suffers from several disadvantages, most notably, skin irritation, particularly for treatment naïve patients. In this prospective, randomized, controlled, split-face study, we evaluated the comparative efficacy, safety, and tolerability of a novel 3-step azelaic acid, salicylic acid, and graduated retinol regimen versus a common OTC BPO-based regimen over 12 weeks. A total of 37 adult subjects with self-reported mild to moderate acne vulgaris were recruited. A total of 21 subjects underwent a 2-week washout period and completed the full study with 3 dropping out due to product irritation from the BPO routine, and 13 being lost to follow-up. Detailed tolerability surveys were conducted at Week 4. Additional surveys on tolerability and product preferences were collected monthly, at Week 4, Week 8, and Week 12. A blinded board-certified dermatologist objectively scored the presence and type of acne lesions (open or closed comedones, papules, pustules, nodules, and cysts) at baseline, Week 4, Week 8, and Week 12. Patients photographed themselves and uploaded the images using personal mobile phones. Detailed Week 4 survey results showed across 25 domains of user-assessed product performance, the novel routine outperformed the BPO routine in 19 (76%) which included domains in preference (e.g. "I would use this in the future) and performance ("my skin improved" and "helped my acne clear up faster"). Users of the novel routine reported less facial redness, itching, and burning, though differences did not reach statistical significance. In terms of efficacy, both products performed similarly, reducing total acne lesions by 36% (novel routine) and 40% (BPO routine) by Week 12. Overall, accounting for user preferences and tolerability the novel routine was more preferred than the BPO routine in 79% of domains (22/28). Differences in objective acne lesion reduction were not statistically significant (p = 0.97). In a randomized split-face study, a 3-step azelaic acid, salicylic acid, and graduated retinol regimen delivered similar acne lesion reduction, fewer user dropouts, greater user tolerability, and higher use preference compared to a 3-step BPO routine based in a cohort of participants with mild-to-moderate acne vulgaris.

From consistent subjective assessment of skin sensitivity severity to its accurate objective scoring

BACKGROUND

Sensitive skin (SenS) is a syndrome leading to unpleasant sensations with little visible signs. Grading its severity generally relies on questionnaires or subjective ratings.

MATERIALS AND METHODS

The SenS status of 183 subjects was determined by trained assessors. Answers from a four-item questionnaire were converted into numerical scores, leading to a 0-15 SenS index that was asked twice or thrice. Parameters from hyperspectral images were used as input for a multi-layer perceptron (MLP) neural network to predict the four-item questionnaire score of subjects. The resulting model was used to evaluate the soothing effect of a cosmetic cream applied to one hemiface, comparing it to that of a placebo applied to the other hemiface.

RESULTS

The four-item questionnaire score accurately predicts SenS assessors' classification (92.7%) while providing insight into SenS severity. Most subjects providing repeatable replies are non-SenS, but accepting some variability in answers enables identifying subjects with consistent replies encompassing a majority of SenS subjects. The MLP neural network model predicts the SenS score of subjects with consistent replies from full-face hyperspectral images (R2 Validation set  = 0.969). A similar quality is obtained with hemiface images. Comparing the effect of applying a soothing cosmetic to that of a placebo revealed that subjects with the highest instrumental index (> 5) show significant SenS improvement.

CONCLUSION

A four-item questionnaire enables calculating a SenS index grading its severity. Objective evaluation using hyperspectral images with an MLP neural network accurately predicts SenS severity and its favourable evolution upon the application of a soothing cream.

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.

Psychological Aspects of Sensitive Skin: A Vicious Cycle

Sensitive Skin Syndrome (SSS) has been the subject of intense research in the past several years. Recent reviews confirm that about 40% of the population report moderate or very sensitive skin, and an additional 30% report slightly sensitive skin. Although certain phenotypes are more susceptible, anyone can suffer from SSS and this condition can manifest in all anatomic sites. A wide variety of environmental and lifestyle factors can trigger SSS symptoms of itching, stinging, burning, pain, and tingling. In order to avoid such triggers, the SSS individuals often alter their behaviors and habits such as restricting their daily activities, and modifying the use of everyday products that non-sensitive individuals take for granted. In addition, there is an association between SSS and some common psychological problems. Sensitive skin symptoms such as itching, stinging, burning and pain can result in sleep disorders, fatigue, stress and anxiety. Conversely, lack of sleep and stress from external sources can make the SSS sufferer more prone to the symptoms. This becomes a vicious cycle that impacts consumers’ quality of life and well-being. We are beginning to understand the importance of the underlying causes that can impact skin conditions. However, in order to better understand the SSS individual, we need to also be aware of the psychological factors that can trigger and/or worsen this skin condition, as well as the psychological stresses the condition places on the individual.

Sensitive skin: A relevant syndrome, be aware

Sensitive skin is clinically defined by characteristic sensory perceptions including tightness, abnormal stinging, burning, tingling, pain and pruritus. Facial erythema may occur, and other body areas can be involved. Sensitive skin affects extremely the quality of life. According with the International Forum for the Study of Itch (IFSI), sensitive skin is defined as a syndrome. The unpleasant sensations described are in response to stimuli that normally should not provoke such sensations. Moreover, these unpleasant sensations cannot be explained by any skin disease. Sensitive skin is always considered when any new consumer health, cosmetic or household product is introduced in the market. Once sensitive skin is recognized, it is mandatory to identify specific triggers that commonly induce symptoms and even cutaneous visible signs. Sensitive skin syndrome can be exacerbated by an allergic setting and environmental factors (cold, hot, dryness, pollution, wind, chemicals ...), a source of intolerance and unpleasant sensations. Cosmetics are the main triggering factors of sensitive skin according to patient's reports. The presence of potentially irritant substances in their composition increases the clinical expression of symptoms. As sensitive skin is frequent, and it is increasing based on the current development of cosmetic use worldwide, there is a need to develop better skin care products. The continuous research of active and safe skin care products to prevent and treat sensitive skin is extremely welcome.

Specific protection of sensitive skin against environmental stress by maintenance and improvement of barrier function

BACKGROUND

Sensitive skin is a common condition that can severely impact quality of life. Several mechanisms are thought to be involved, including those affecting the skin barrier function, hydration and skin innervation.

OBJECTIVES

To investigate the benefit of cream and balm formulations dedicated to sensitive skin and containing Aquaphilus dolomiae extract-G3 (ADE-G3) on skin barrier functions (lipid composition, pH, TEWL), as well as protective responses to dry and pollution stresses.

METHODS

In vitro sensitized (using histamine) reconstructed human epidermis (RHE) were subjected to dehydration and pollution stress in the absence and presence of the formulations. Endpoint measurements included transepithelial electric resistance (TEER), stratum corneum protein expression and lipid contents. Clinical measurements included transepithelial water loss (TEWL), skin pH and the lipid index.

RESULTS

When applied in cream and balm formulations, ADE-G3, increased the TEER in sensitized RHEs. In non-sensitized dehydrated RHEs, both formulations increased recovery of skin barrier integrity after dehydration, evident as a return of the ratios of filaggrin/profilaggrin and caspase-14/procaspase-14 to values measured in control non-stressed RHEs, as well as reducing the 'natural moisturizing factor' to control levels. In clinical studies performed on dry human skin, the formulations helped to maintain and improve the skin barrier function. This was evident as an intense and sustained moisturization (total lipids and lipid esters were increased), an increase in pH and a decrease in the TEWL by both formulations. When exposed to pollution stress by treating the models with benzo[a]pyrene and airborne particulate matter (PM10), application of both formulations prior to exposure attenuated the induction of CYP1A1, CYP1B1 and UGT1A7 expression, indicating a protective effect.

CONCLUSIONS

ADE-G3 cream and balm formulations increased the hydration of the skin but also protected and improved the skin barrier integrity of sensitive skin exposed to dry and cold and airborne pollutant-induced stress environments.

Occurrence of Allergens in Cosmetics for Sensitive Skin

Sensitive skin is characterized by symptoms such as stinging and tingling in response to stimuli that usually do not cause unpleasant sensations. Epidemiological studies show that individuals with sensitive skin are more prone to developing skin allergies, although the link between both conditions is unknown. Aiming to evaluate the presence of allergens in facial-skin products for sensitive skin, a pool of 88 cosmetic products from international brands marketed in pharmacies and parapharmacies was analyzed. A list of allergens identified in product labels was compiled and grouped according to their function. Fragrances were the most common allergens, followed by skin-conditioning agents, surfactants, and preservatives. Fragrances presenting the highest use percentages were linalool, benzyl alcohol, geraniol, and citronellol. Overall, the majority of cosmetic formulations were absent of fragrance allergens, being present only in 7% of products. Other allergens were found in most products (95%). This finding should be interpreted with caution, since many of these compounds are rare sensitizers and studies demonstrating their risk for individuals with sensitive skin are lacking. With this study, useful information for health professionals is provided to support their advice and to help consumers choosing cosmetic products.

Sensitive skin: Active ingredients on the spotlight

OBJECTIVE

Sensitive skin is characterized by self-reported sensory perceptions in response to stimuli that should not provoke unpleasant sensations. Cosmetic products for sensitive skin are designed to minimize these symptoms. This study aimed to unveil the most used active ingredients for sensitive skin in facial care products from the pharmacy and parapharmacy channel.

METHODS

A pool of products from the pharmacy and parapharmacy channel whose label included the expressions 'sensitive skin', 'reactive skin' or 'intolerant skin' were analysed. The active ingredients were identified from product compositions and ranked in descending order of occurrence. The scientific evidence regarding the mechanism of action and efficacy of each ingredient was also compiled.

RESULTS

Eighty-eight products from 19 multinational brands were included. Niacinamide leads the top, followed by Avena sativa, allantoin, glycyrrhetinic acid and derivatives and Laminaria ochroleuca. Ingredients that can reduce skin inflammation and act on the skin barrier were used in more than half of the products analysed. The clinical studies regarding the active ingredients used in these products remain sparse and lack methodological quality. Among the top ingredients, niacinamide, panthenol and acetyl dipeptide-1 cetyl ester were the only ones studied on volunteers having sensitive skin, while acetyl dipeptide-1 cetyl ester and palmitoyl tripeptide-8 were designed to act on the molecular targets involved in this condition.

CONCLUSION

This study reveals the most used active ingredients in cosmetic products for sensitive skin, as well as the scientific evidence supporting their efficacy and the mechanisms of action. This insight is meaningful for dermatologists and other health professionals to provide customized advice based on the symptomatology of individuals with sensitive skin, and for the formulation of cosmetic products and design of new active ingredients.

The prevalence and characterization of self-perceived sensitive facial skin among Freshmen in Urumqi, China

BACKGROUND

The clinical signs, symptoms, and the etiology of sensitive skin (SS) in general populations have been extensively studied over the last decades, but the characteristics of SS in Xinjiang, particularly the age-related characteristics, still remain unknown.

OBJECTIVE

This study aimed to characterize the SS facial skin in normal adolescents of Xinjiang.

METHODS

A questionnaire was developed based on SS and given to each participant. The clinical signs, symptoms, associated trigger factors, and DQLI of facial SS were compared in normal young Chinese males versus females.

RESULTS

A total of 3584 freshmen were investigated, wherein 83 were diagnoses as self-reported facial SS (2.3%). The prevalence of SS was found to be significantly higher in females than in males. Spicy food, mood change, and skin care products are the major contributors to facial SS (p < 0.01). Moreover, family history and sun exposure are closely related to the onset of SS (p < 0.05). More SS patients were sensitive to emotional factors and had a greater difficulty with shopping or housework, dressing, socializing, or other leisure activities. The main manifestations of SS are flushing, erythema, and dry skin on buccal, frontal, and temporal sputum. The symptoms mainly include skin burning and dry itching, and two or more symptoms at the same time. The absolute value of red area and pores of SS were higher than that of normal skin (p < 0.05).

CONCLUSIONS

The prevalence, symptoms, clinical characteristics, and triggering factors of facial SS in normal young of Xinjiang, especially freshmen in the 17-21 age group, were not similar with SS, which might be due to racial and regional differences.

Questionnaire and Lactic Acid Sting Test Play Different Role on the Assessment of Sensitive Skin: A Cross-sectional Study

BACKGROUND

Questionnaires and lactic acid sting test (LAST) are two widely used methods to identify sensitive skin. However, the self-perceived sensitive skin by questionnaires was not consistent with the determination of LAST.

OBJECTIVE

The aim of the study was to measure the biophysical properties noninvasively of sensitive skin evaluated by questionnaire and LAST and to investigate their correlations with the scores of questionnaire and LAST.

METHODS

A total of 209 healthy Chinese females completed the study. Self-assessment questionnaire and LAST were both performed to identify sensitive skin. Epidermal biophysical properties, including skin hydration, transepidermal water loss (TEWL), sebum content, erythema index (EI), a* value, L* value, skin elasticity, and skin pH, were measured with noninvasive instruments.

RESULTS

The frequency of sensitive skin was 50.2% and 66.0% by questionnaire and LAST, respectively. Subjects with self-assessed sensitive skin had a slightly higher LAST positive rate. Skin hydration, sebum content, a* and EI values were significantly higher in the self-assessed sensitive skin group, while TEWL, a* and EI values increased but L* value decreased with significance in the LAST positive group. The LAST stingers among sensitive skin subjects had higher EI but not in the healthy skin subjects. In addition, questionnaire scores positively correlated with skin hydration, sebum content, a* and EI values, while a positive relationship of LAST scores with TEWL, a* and EI values was observed. The scores of questionnaire and LAST both negatively related to L* value.

CONCLUSION

Self-assessed questionnaire is associated with sensitive skin featured by oily and red face without impaired barrier function, whereas LAST is suitable to identify fragile skin barrier and enhanced blood flow on the face. Combination of both methods to diagnose sensitive skin might be more reliable.

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.

Understanding the Sensitive Skin Subject to Achieve a More Holistic Diagnosis

Sensitive skin Syndrome (SSS) is a complex global clinical phenomenon that is defined by the self-reported presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus and often without objective signs. Due to the subjective nature of this clinical condition, the diagnosis is complex and there is often a disconnect between what subjects feel and what medical professionals can observe. This chapter reviews the known underlying physiology, some of the triggering factors associated with SSS, co-morbidities as well as the psychological impact on individuals suffering from this condition. The goal is to bridge the gap between the physicians’ understanding and the subjects’ perceptions of this real-life condition that affects so many.

Marine Ingredients for Sensitive Skin: Market Overview

Marine ingredients are a source of new chemical entities with biological action, which is the reason why they have gained relevance in the cosmetic industry. The facial care category is the most relevant in this industry, and within it, the sensitive skin segment occupies a prominent position. This work analyzed the use of marine ingredients in 88 facial cosmetics for sensitive skin from multinational brands, as well as their composition and the scientific evidence that supports their efficacy. Marine ingredients were used in 27% of the cosmetic products for sensitive skin and included the species Laminaria ochroleuca, Ascophyllum nodosum (brown macroalgae), Asparagopsis armata (red macroalgae), and Chlorella vulgaris (microalgae). Carotenoids, polysaccharides, and lipids are the chemical classes highlighted in these preparations. Two ingredients, namely the Ascophyllum nodosum extract and Asparagopsis armata extracts, present clinical evidence supporting their use for sensitive skin. Overall, marine ingredients used in cosmetics for sensitive skin are proposed to reduce skin inflammation and improve the barrier function. Marine-derived preparations constitute promising active ingredients for sensitive skin cosmetic products. Their in-depth study, focusing on the extracted metabolites, randomized placebo-controlled studies including volunteers with sensitive skin, and the use of extraction methods that are more profitable may provide a great opportunity for the cosmetic industry.

Use of Cosmetic Products in Real Life by Women with Facial Sensitive Skin: Results from an Exposure Study and Comparison with Controls

Triggering factors of sensitive skin are supposed to be physical, chemical (cosmetics, water, and pollutants), and occasionally psychological (stress). A recent meta-analysis showed that the most important triggering factor declared by subjects is the use of cosmetics. This study was designed to compare the consumption of cosmetic products in women with sensitive skin and controls. After a dermatological examination, women between the ages of 18 and 65 years with or without sensitive skin were recruited. They completed different questionnaires about the presence of sensitive skin and use of 28 cosmetics that could be applied on the face. The amount per application was recorded for all products used at least once a week on the face. In total, 160 women were included, with a mean age of 41 ± 13 years. Two groups of 40 women were created based on the sensitive scale (SS-10 score), with the lowest SS-10 scores (nonsensitive skin group) and the highest SS-10 score (sensitive skin group). The number of products used daily was similar in the 2 groups. Women with sensitive skin were significantly more frequent users of liquid soap/soap-free gel cleansers than those without sensitive skin (70 vs. 43%). There was no difference concerning the frequency of use of products in the 2 groups. Concerning the amount of product used by application, women with sensitive skin used twice as much cream per application compared with the women without sensitive skin: 511 ± 438 μg versus 290 ± 203 μg (p = 0.039). Concerning the composition of the cosmetic products used, the only difference concerned phenoxyethanol, which was more often present in the moisturizer of women without sensitive skin (66.7%) than in those with sensitive skin (32.4%) (p = 0.007). Women with sensitive skin were more likely to buy products recommended for sensitive skin by manufacturers. The relationship of causality between the use of cosmetics and sensitive skin cannot be established. Women with sensitive skin used different cosmetic products than women without sensitive skin. Women with sensitive skin used a higher amount of moisturizer, used products recommended for sensitive skin, and bought more cosmetic products at pharmacies than supermarkets. We hypothesized that subjects with sensitive skin are looking for products that improve the sensation of skin sensitivity.

Usage of Synthetic Peptides in Cosmetics for Sensitive Skin

Sensitive skin is characterized by symptoms of discomfort when exposed to environmental factors. Peptides are used in cosmetics for sensitive skin and stand out as active ingredients for their ability to interact with skin cells by multiple mechanisms, high potency at low dosage and the ability to penetrate the stratum corneum. This study aimed to analyze the composition of 88 facial cosmetics for sensitive skin from multinational brands regarding usage of peptides, reviewing their synthetic pathways and the scientific evidence that supports their efficacy. Peptides were found in 17% of the products analyzed, namely: acetyl dipeptide-1 cetyl ester, palmitoyl tripeptide-8, acetyl tetrapeptide-15, palmitoyl tripeptide-5, acetyl hexapeptide-49, palmitoyl tetrapeptide-7 and palmitoyl oligopeptide. Three out of seven peptides have a neurotransmitter-inhibiting mechanism of action, while another three are signal peptides. Only five peptides present evidence supporting their use in sensitive skin, with only one clinical study including volunteers having this condition. Noteworthy, the available data is mostly found in patents and supplier brochures, and not in randomized placebo-controlled studies. Peptides are useful active ingredients in cosmetics for sensitive skin. Knowing their efficacy and synthetic pathways provides meaningful insight for the development of new and more effective ingredients.

Analysis of the Bacterial Flora of Sensitive Facial Skin Among Women in Guangzhou

Background

Sensitive skin (SS) is easily irritated by various environmental stimuli, and epidemiological surveys surprisingly find that self-perceived SS is widespread worldwide.

Objective

To investigate whether SS is linked to changes in the skin bacterial population using 16S rRNA sequencing and bioinformatic analysis.

Patients and Methods

According to both the Huaxi SS Questionnaire and Lactic Acid Stimulation Test, 60 female volunteers in Guangzhou were classified into normal skin (NS) and SS groups. Skin barrier parameters were assessed by the CK skin tester. The DNA of the bacterial flora on the facial skin surface was extracted and was subjected to 16S rRNA sequencing.

Results

The skin hydration was significantly lower in the SS group compared to the NS group (P =0.032). Based on 16S rRNA sequencing and bioinformatic analysis, the number of operational taxonomic units (OTUs) significantly decreased in the SS group (P =0.0235, SS vs NS). The relative abundance of Neisseriaceae in SS group decreased significantly (P <0.05, SS vs NS), while that of Neisseria (within the Neisseriaceae family) increased significantly (P <0.05, SS vs NS).

Conclusion

SS is accompanied by a decrease in species diversity and richness, which may be relevant to the weakening of the microbial barrier (due to the increase of Neisseria or the decrease of Neisseriaceae). Thus, corresponding treatment for Neisseriaceae may be a new idea in the treatment of SS.

Demodex infestation as a cause of sensitive skin in a dermatology outpatient clinic

BACKGROUND

Sensitive skin is subjective cutaneous hyperreactivity to environmental factors. Demodicosis is a skin disorder caused by Demodex mites. There may be a link between demodicosis and sensitive skin.

AIM

This study aimed to examine facial Demodex mites density and other factors associated with sensitive skin in patients.

METHODS AND METHODS

A total of 349 randomly selected patients presented to the dermatology department. The research data were collected using a questionnaire form that included the participants' sociodemographic and lifestyle characteristics, a sensitive skin questionnaire, the Dermatology Life Quality Index (DLQI), and European Health Interview Survey (EHIS). Patients underwent standardized superficial skin surface biopsy of 4 areas of the face. D. folliculorum count greater than 5 mites/cm² was considered positive.

RESULTS

In relation to Demodex, there was an increase in skin sensitivity with higher Demodex density (p = 0.04). There was a statistically significant, weak positive correlation between skin sensitivity and DLQI score (r = 0.33, p = 0.00), and there was also a significant but very weak negative correlation between skin sensitivity and EUROHIS (r = -0.164, p = 0.002). Skin sensitivity was more common in patients with a concomitant dermatological disease (p = 0.01) and increased with more frequent cosmetic use (p = 0.00).

CONCLUSION

Alongside other risk factors, for the patients presenting with complaints of sensitive skin, investigating Demodex population density may help alleviate sensitive skin symptoms with appropriate therapies and preventive measures.

Relationship between sensitive skin and sleep disorders, fatigue, dust, sweating, food, tobacco consumption or female hormonal changes: Results from a worldwide survey of 10 743 individuals

BACKGROUND

Sensitive skin is related to environmental factors.

OBJECTIVES

We aimed to investigate the roles of poorly known associated and triggering factors on sensitive skin in a large global population.

METHODS

A survey was administrated to a representative sample of the adult population aged 18-75 years in five different countries (Brazil, China, France Russia, and the United States). All participants answered a web-based questionnaire on sociodemographic characteristics, sensitive skin and environmental factors.

RESULTS

Among the 10 743 included individuals (5285 men and 5458 women), 48.2% declared that they had sensitive skin. The group with sensitive skin reported significant increases in fatigue, dust or sweating and to a lesser extent food or tobacco consumption. The members of this group also declared that they experienced more sleep disorders than individuals without sensitive skin. Sensitive skin was very frequent in pregnant women, women with painful menstruations or women using contraceptive pills.

CONCLUSIONS

This large cohort study identified new factors, including female hormonal status, fatigue, sleep disorders and food, associated with sensitive skin. These associations suggest that sensitive skin is not restricted to an epidermal disorder but may be included in a larger context. The identified factors are potential upstream drivers of neurogenic inflammation in sensitive skin.

Genome-Wide Association Study Identifies Loci Associated with Sensitive Skin

Individuals suffering from sensitive skin often have other skin conditions and/or diseases, such as fair skin, freckles, rosacea, or atopic dermatitis. Genome-wide association studies (GWAS) have been performed for some of these conditions, but not for sensitive skin. In this study, a total of 23,426 unrelated participants of European ancestry from the 23andMe database were evaluated for self-declared sensitive skin, other skin conditions, and diseases using an online questionnaire format. Responders were separated into two groups: those who declared they had sensitive skin (n = 8971) and those who declared their skin was not sensitive (controls, n = 14,455). A GWAS of sensitive skin individuals identified three genome-wide significance loci (p-value < 5 × 10−8) and seven suggestive loci (p-value < 1 × 10−6). Of the three most significant loci, all have been associated with pigmentation and two have been associated with acne.