Cutaneous vessel features of sensitive skin and its underlying functions

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.

Non-invasive efficacy assessment of pulsed dye laser and photodynamic therapy for port-wine stain

Port wine stain (PWS) is a congenital vascular malformation that commonly occurs on the face and neck. Currently, the main treatments for port wine stain are pulsed dye laser (PDL) and photodynamic therapy (PDT). However, the efficacy evaluation of PWS mostly relies on the subjective judgement of clinicians, and it is difficult to accurately respond to many small changes after treatment. Therefore, some non-invasive and efficient efficacy assessment methods are also needed. With the continuous development of technology, there are currently many visualisation instruments to evaluate PWS, including dermoscopy, VISIA-CR™ system, reflectance confocal microscopy (RCM), high-frequency ultrasound (HFUS), optical coherence tomography (OCT), Photoacoustic imaging (PAI), laser speckle imaging (LSI) and laser Doppler imaging (LDI). Among them, there are simple and low-cost technologies such as dermoscopy and the VISIA-CR™ system, but they may not be able to observe the deeper structures of PWS. At this time, combining techniques such as HFUS and OCT to increase penetration depth is crucial to evaluate PWS. In the future, the combination of these different technologies could help overcome the limitations of a single technology. This article provides a systematic overview of non-invasive methods for evaluating treatment efficacy in port wine stains and summarises their advantages and disadvantages.

Lactic acid sting test and capsaicin test differentially induce facial erythematous reaction in subjects with sensitive skin

BACKGROUND

Sensitivity skin (SS) is a common skin disorders, which have a various of clinical manifestation. Facial erythema is common objective symptom of SS. However, the reasons for the occurrence of erythema in sensitive skin are not fully understood.

AIMS

In this study, we preliminarily explain the possible factors inducing erythema of sensitive skin by evaluating facial erythematous reaction to lactic acid sting test (LAST) and capsaicin test (CAT) in subjects with sensitive skin.

METHODS

A total of 197 subjects were divided into five groups, that is, normal controls (NC), LAST-positive (LAST+ ), both LAST and CAT positive (L+ C+ ), both LAST and CAT negative (L- C- ) and CAT-positive (CAT+ ). Erythema index (EI), a* value, and tissue viability imaging (TIVI) were measured before and after LAST and CAT, The ΔEI, Δa*, and ΔTIVI before and after LAST and CAT were calculated, and the correlation between the scores of CAT, EI values, a* values, and TIVI values were analyzed to clarify the causes of facial erythema.

RESULTS

Our results showed that EI values and a* values were significantly higher in the L+ C+ and CAT+ group than in NC group, TIVI values were higher in the L+ C+ group than in NC group. ΔEI and Δa* values after LAST did not differ significantly among five groups. However, ΔEI values in L+ C+ group were higher than that in L- C- group, while Δa* values were higher in CAT+ group than in NC. Moreover, ΔTIVI values in L+ C+ group and CAT+ group were also significantly higher than that in NC group after capsaicin stimulation. CAT scores correlated positively with EI, a* and TIVI values.

CONCLUSION

Our results suggest that sensitive skin subjects with positive CAT are more likely to experience erythema reactions, and vasodilation is more pronounced after capsaicin stimulation. Reducing vascular and neural hyperreactivity could be therapeutic target in management of facial erythema in subjects with sensitive skin.

Rosacea and seborrheic dermatitis differentially respond to lactic acid sting and capsaicin tests in Chinese women

BACKGROUND

Although rosacea and seborrheic dermatitis share some symptoms of sensitive skin, whether they respond differently to lactic acid sting and capsaicin tests, common tests for diagnosis of sensitive skin, is unknown.

OBJECTIVES

To reveal the cutaneous responses to lactic acid sting (LAST) and capsaicin test (CAT) in females with either rosacea vs. seborrheic dermatitis.

METHODS

A total of 60 patients with rosacea, 20 patients with seborrheic dermatitis and 40 normal controls were enrolled in the study. Their skin sensitivity to stimuli were evaluated following topical application of either 10% lactic acid solution or 0.001% capsaicin solution. Transepidermal water loss (TEWL) rates and erythema indexes were also measured on the face.

RESULTS

In comparison to normal controls, the positive rate to either LAST or CAT was significantly higher in subjects with rosacea (p < 0.001), but not in that with seborrheic dermatitis. Similarly, individuals with rosacea displayed a higher positive rate to both LAST and CAT than those with seborrheic dermatitis and normal controls (p < 0.001). In parallel, the LAST scores and CAT scores in individuals with rosacea were significantly higher than in that with either seborrheic dermatitis or normal controls (p < 0.001). The baseline TEWL rates and erythema indexes were higher in individual with rosacea than in normal controls (p < 0.001). But the baseline TEWL rates and erythema indexes did not differ significantly between subjects with rosacea and that with seborrheic dermatitis. Moreover, LAST scores and CAT scores correlated positively with TEWL (p < 0.0001). TEWL rates were higher in CAT positive than in CAT negative subjects (p < 0.0001). Finally, erythema index correlated positively with CAT scores (p < 0.0001), but not with LAST scores (p = 0.0842).

CONCLUSIONS

Skin responses to LAST and CAT differ between individuals with rosacea and those with seborrheic dermatitis, possibly due to the differences in epidermal permeability barrier and the neurovascular hyperreactivity. The higher LAST and CAT scores, as well as positive rates of both LAST and CAT can be attributable to inferior permeability barrier and the neurovascular hyperreactivity in subjects with rosacea.

ICNIRP Guidelines' Exposure Assessment Method for 5G Millimetre Wave Radiation May Trigger Adverse Effects

The current global roll-out of 5G infrastructure is designed to utilise millimetre wave frequencies (30-300 GHz range) at data transmission rates in the order of gigabits per second (Gbps). This frequency band will be transmitted using beamforming, a new introduction in near-field exposures. The International Commission on Non-Ionising Radiation Protection (ICNIRP) has recently updated their guidelines. We briefly examine whether the new approach of the ICNIRP is satisfactory to prevent heat damage and other adverse bio-effects once millimetre wave 5G is included, and we challenge the use of surface-only exposure assessment for local exposures greater than 6 GHz in part due to possible Brillouin precursor pulse formation. However, this is relevant whether or not Brillouin precursors occur from absorption of either 5G or future G transmissions. Many significant sources conclude there is insufficient research to assure safety even from the heat perspective. To date, there has been no published in vivo, in vitro or epidemiological research using exposures to 5G New Radio beam-formed signals.

The Challenges in Investigating the Pathogenesis of Sensitive Skin by Noninvasive Measurements: A Systematic Review

Sensitive skin (SS) is a common cutaneous condition that seriously affects people's quality of life, but studies of sensitive skin pathogenesis are unclear, the exploration are ongoing, and the biophysical properties of sensitive skin disagree with the study results. In this paper, we summarize the noninvasive biophysical and imaging instrumental methods used for sensitive skin and provide support for the classification of sensitive skin subtypes to prescribe precise treatment. PubMed and Web of Science databases were searched according to PRISMA guidelines for articles from January 1971 to May 2022 that used noninvasive biophysical or imaging methods to monitor adult subjects with sensitive skin. The quality of the included articles was determined based on 22 items of the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement. A total of 55 studies were included, representing 8 biophysical and 5 imaging methods and their applications in treatment efficacy evaluation studies. The biophysical parameter and cutaneous morphological property changes in sensitive skin subjects were observed. The quality of the studies was relatively low, and there was high variability in results between studies. Several parameters have shown tremendous potential in exploring the pathogenesis with different sensitive skin subtypes: type I may be detected with higher transepidermal water loss and lower stratum corneum hydration values, as well as with thinner epidermis with a shallower and more irregular honeycomb structure; Type II and III are more prone to higher blood flow, lower current perception threshold than normal skin. This systematic review identifies key reasons for the lack of uniform trends in noninvasive measurements and recommends the use of effective selection instruments or relevant parameters to explore the pathogenesis of sensitive skin, and to differentiate the subtypes of sensitive skin for achieving the precise treatment.

Quantitative evaluation of sensitive skin by ANTERA 3D ® combined with GPSkin Barrier ®

BACKGROUND

At present, there are many different evaluation methods for sensitive skin, including subjective, semisubjective, and objective evaluation. Various objective tests focus on assessing changes in barrier functions. It is anticipated that the ANTERA 3D®, in combination with GPSkin Barrier®, will provide better evaluation of sensitive skin.

METHODS

A total of 20 subjects with sensitive skin and 20 healthy participants were recruited. Sensitive skin subjects were treated with an anti-sensitive moisturizing tolerance-extreme cream which has anti-inflammatory and moisturizing effects, twice daily on the whole face for 28 days. VISIA^® Skin Detector was used to record clinical images and red area. GPSkin Barrier^® was used to measure TEWL and SCH. Texture, hemoglobin, and influenced area (mm² ) were recorded using ANTERA 3D^® . Subjects underwent skin tests and recorded changes at D0 and D28. Data were only collected from healthy participants who did not receive treatment as controls.

RESULTS

TEWL, texture, hemoglobin, and affected area in sensitive skin group were significantly higher than those in healthy group, while SCH was significantly lower than that in healthy group (p all<0.05). After anti-inflammatory and moisturizing treatment, the texture, hemoglobin, and affected area of sensitive skin decreased, TEWL decreased while SCH increased (p all<0.05).

CONCLUSIONS

Based on the results, the combination of the ANTERA 3D^® with GPSkin Barrier^® could be used as a new kind of quantitative evaluation method for the detection and diagnosis of sensitive skin.

Hemoporfin-Mediated Photodynamic Therapy for Port-Wine Stains: Multivariate Analysis of Clinical Efficacy and Optical Coherence Tomography Appearance

Background

Hemoporfin-mediated photodynamic therapy (HMME-PDT) is reported to be effective and safe for port-wine stains (PWS). However, its efficacy is influenced by several factors and there is no appropriate method to evaluate efficacy so far. Therefore, this study explored the clinical efficacy of HMME-PDT for PWS on the face and neck and the feasibility of evaluating treatment potency with optical coherence tomography (OCT).

Methods

A total of 211 PWS patients subjected to HMME-PDT were recruited for study and correlations of therapeutic effect with treatment sessions, age, gender, lesion distribution and treatment history analyzed. OCT was utilized for quantitative analysis of PWS lesions of 36 selected patients before and after HMME-PDT.

Results

The efficacy of two consecutive treatments was significantly higher than that of single treatment (P < 0.05). In multivariate analysis, after the first treatment, age, lesion distribution and treatment history were correlative factors affecting treatment efficacy (P < 0.05). The improvement effect on central facial lesions was lower than that on lateral facial lesions (P < 0.05). The efficacy of therapy on the group with no history of pulsed dye laser (PDL) treatment was greater than that on effective and ineffective treatment groups (P < 0.05). After the second session, age remained the only factor correlated with efficacy (P < 0.05). Dilated vessel diameter and depth before and after treatment were significantly different (P < 0.05). With increasing treatment times, age was the most significant factor influencing treatment efficacy.

Conclusions

Our collective findings indicate that HMME-PDT therapy is effective and safe for PWS and support the utility of OCT in objective assessment of the efficacy of HMME-PDT.

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.

Study of the protective effects of cosmetic ingredients on the skin barrier, based on the expression of barrier-related genes and cytokines

Background

Sensitive skin is the result of a complex process that is closely linked to the damage of the skin barrier. There are no recognized methods for evaluating the efficacy of anti-allergy products.

Methods

In this study, a model of skin barrier damage was created by treating HaCaT cells with 60 μg/ml of sodium dodecyl sulfate for 48 h. The protective effects of nine cosmetic ingredients, including oat extract (S1), on the skin barrier were investigated based on the gene expression levels of aquaporin3 (AQP3), filaggrin (FLG), caspase-14 (CASP14), and human tissue kallikrein7 (KLK7), as well as those of various interleukins (IL) and vascular endothelial growth factor (VEGF).

Results

Among the nine ingredients, S1 had a good protective effect on the function of the skin barrier. It promoted the expression of AQP3, FLG, and CASP14, while inhibiting the expression of KLK7 in HaCaT cells, at a concentration of 0.06%. It also maintained IL-6, IL-8, and VEGF at appropriate levels while promoting the proliferation and differentiation of HaCaT cells.

Conclusions

The above indicators allow for the preliminary establishment of a method to evaluate the efficacy of the barrier protection ability of sensitive skin.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-021-06918-5.

Seasonal changes in the physiological features of healthy and sensitive skin

BACKGROUND

The effects of seasonal factors on sensitive skin (SS) have been reported intensively, but the mechanisms still remain poorly understood.

OBJECTIVE

To investigate the effects of seasonal factors on SS, by comparing the physiological changes in the healthy skin and different subgroups of SS with seasonal variation.

METHODS

Through a questionnaire survey, lactic acid sting test, and capsaicin test, qualified subjects were classified into four groups: healthy skin, only lactic acid sting test positive (LAST(+)/CAT(-)), only capsaicin test positive (LAST(-)/CAT(+)), and both positive (LAST(+)/CAT(+)). Skin physiological parameters were measured in winter and summer.

RESULTS

A total of 140 subjects completed the study. Significant differences were found in transepidermal water loss (TEWL), skin pH, and cutaneous blood flow (CBF) between winter and summer in the four groups. There were significant differences in stratum corneum hydration (SCH) of the LAST(+)/CAP(-) and LAST(+)/CAP(+) groups, current perception threshold (CPT) at 250 Hz of the LAST(+)/CAT(+) group, and epidermal density of the healthy skin group between the two seasons. Sum of the scores of sting (SSS) showed a close correlation with TEWL, SCH, pH, CPT at 250 Hz, and epidermal density. Sum of the scores of burning (SSB) showed a strong correlation with TEWL, pH, CPT at 250 Hz and 5 Hz, and epidermal density.

CONCLUSIONS

Seasonal variation influences the skin barrier function of different types of sensitive skin at different levels. We therefore strongly suggest that, with seasonal variation, different treatments will be undertaken for different subgroups of sensitive skin.

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.

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.

Cutaneous vessel features of sensitive skin and its underlying functions

Background

Following the sufficient studies of the effects of skin barrier impairment and heightened neural reaction on sensitive skin (SS), many scholars have paid great attention to the roles of superficial microvasculature in SS.

Methods

By questionnaire survey, lactic acid sting test, and capsaicin test, eligible subjects were classified as normal skin, only lactic acid sting test positive (LASTP), only capsaicin test positive (CATP), and both positive (both LASTP and CATP). D‐OCT was used to photograph images for evaluating the cutaneous vessels features each group.

Results

Totally 137 subjects completed the study. Compared with LASTN group, the vascular vessels were closer to epidermis in LASTP group. Mesh and branching vessels were more popular in SS than normal skin. High blood vessel density was more prevalent in SS, while low density frequently presented in normal skin. The vascular depth had a closely negative correlation with face flushing and SSS, and vascular shapes had a good positive correlation with face flushing and SSB.

Conclusions

Our study indicates that there is a significant difference in vascular depth, shape, and density between SS and normal skin which is valuable to explore SS pathologic mechanism and to further investigate cutaneous microvasculature functions in SS.