Skin sensitivity evaluation: What could impact the assessment results?

ABCD Classification of Skin Types

The classification of an individual's skin type is important because it helps dermatologists and aesthetic clinicians select the most effective methods for treating the skin. To select suitable cosmetic products and procedures that help ensure healthy and beautiful skin, clinicians must consider the patient's skin type. An individualized classification of skin types allows the clinician to develop personalized skin care recommendations that consider an individual's genetic and physiological characteristics. In the fields of dermatology and aesthetics, the classification of skin types is the basis for scientific research. Skin type classification systems are additionally important for both dermatologists and aesthetic practitioners because they influence the selection of cosmetic products, procedures, and treatments. The purpose of this paper was to provide a detailed review and evaluation of the relevance, suitability, and benefits of the new ABCD Classification of Skin Types, to compare it with other systems for classifying skin types, and to identify parameters for its improvement.

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 effect of tomato and lycopene on clinical characteristics and molecular markers of UV-induced skin deterioration: A systematic review and meta-analysis of intervention trials

Lycopene as a natural antioxidant that have been studied for ultraviolet radiation (UVR) photo protection and is one of the most effective carotenoids to scavenge reactive oxygen species (ROS). This review aims to summarize the protective effect of tomato and lycopene on skin photo damage and skin photoaging in healthy subjects by reviewing the existing population intervention experiments. A total of five electronic databases including PubMed, Scopus, EBSCO, Web of Science and Cochrane Library were searched from inceptions to January 2021 without any restriction. Out of 19336 publications identified, 21 fulfilled the inclusion criteria and were meta-analysis. Overall, interventions supplementing tomato and lycopene were associated with significant reductions in Δa*, MMP-1, ICAM-1 and skin pigmentation; while tomato and lycopene supplementation were associated with significant increase in MED, skin thickness and skin density. Based on the results of this systematic review and meta-analysis, supplementation with tomato and lycopene could reduce skin erythema formation and improve the appearance and pigmentation of the skin, thereby preventing light-induced skin photodamage and skin photoaging. Lycopene-rich products could be used as endogenous sun protection and may be a potential nutraceutical for sun protection.

Characteristics of and foundation application among Chinese females with sensitive skin

OBJECTIVE

We conducted a study on women with sensitive skin of various skin tones to analyse their skin characteristics and preferences for foundation shades.

METHODS

Volunteers were categorized based on their individual typological angle, and their preferences were assessed using self-perception and software-based mass aesthetic assessment. The Baumann Questionnaire is a valuable tool for identifying patients with sensitive skin and gaining a comprehensive understanding of their skin sensitivity. The skin characteristics of two groups were compared using a more suitable classification method.

RESULTS

Individuals diagnosed with sensitive skin typically have skin tones classified as Types I, II and III, with Type I being the most common in sensitive skin cases. The sensitive group exhibited higher levels of transepidermal water loss, lighter skin tone, lower yellowness, increased glossiness, higher haemoglobin content, more acne, fewer blackheads, and fewer pores. Among them, Type I skin is characterized by lower elasticity, increased oiliness, higher hydration levels and fewer visible pores. Type II skin is characterized by lower hydration levels, higher oiliness and increased redness. Type III exhibits more pores, decreased oiliness and enhanced elasticity. Foundations No. 2 and No. 3 are fairer than foundations No. 1 and No. 4. In the self-assessment, Type I and Type II subjects preferred No. 3, while Type III subjects preferred No. 1 and No. 4 because they matched their skin tone. The results of the software evaluation showed that popular aesthetics preferred Type I and Type II to use No. 2, and Type III to use No. 2 and No. 3, as they resulted in a fairer complexion.

CONCLUSION

Sensitive skin of different skin tone types confronts different skin problems. The findings also highlight the public's inclination towards lighter foundation shades, despite the common practice of selecting shades that harmonize with one's inherent skin tone.

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.

Factors Participating in the Occurrence of Inflammation of the Lips (Cheilitis) and Perioral Skin

Lip inflammation may manifest as mainly reversible cheilitis, mainly irreversible, or cheilitis connected to dermatoses or systemic diseases. Therefore, knowing a patient’s medical history is important, especially whether their lip lesions are temporary, recurrent, or persistent. Sometimes temporary contributing factors, such as climate and weather conditions, can be identified and avoided—exposure to extreme weather conditions (e.g., dry, hot, or windy climates) may cause or trigger lip inflammation. Emotional and psychological stress are also mentioned in the etiology of some lip inflammations (e.g., exfoliative cheilitis) and may be associated with nervous habits such as lip licking. To better manage cheilitis, it is also helpful to look for potential concomitant comorbidities and the presence of related diseases/conditions. Some forms of cheilitis accompany dermatologic or systemic diseases (lichen, pemphigus or pemphigoid, erythema multiforme, lupus, angioedema, xerostomia, etc.) that should be uncovered. Occasionally, lip lesions are persistent and involve histological changes: actinic cheilitis, granulomatous cheilitis, glandular cheilitis, and plasmacellular cheilitis. Perioral skin inflammation with simultaneous perioral dermatitis can have various causes: the use of corticosteroids and cosmetics, dysfunction of the skin’s epidermal barrier, a contact reaction to allergens or irritants (e.g., toothpaste, dental fillings), microorganisms (e.g., Demodex spp., Candida albicans, fusiform bacteria), hormonal changes, or an atopic predisposition. Epidermal barrier dysfunction can worsen perioral dermatitis lesions and can also be related to secondary vitamin or mineral deficiencies (e.g., zinc deficiency), occlusive emollient use, sunscreen use, or excessive exposure to environmental factors such as heat, wind, and ultraviolet light. Current trends in research are uncovering valuable information concerning the skin microbiome and disruption of the epidermal barrier of persons suffering from perioral dermatitis. Ultimately, an effective approach to patient management must take all these factors and new research into account.

hMSC exosomes as a novel treatment for female sensitive skin: An in vivo study

Background: Recent studies have reported that the incidence of sensitive skin is increasing. Skin sensitivity and skin barrier functions were related to many skin diseases including atopic dermatitis, psoriasis, rosacea, and so on. Mesenchymal stem cell (MSC)-derived exosomes (hMSC) might be considered as a new effective therapeutic scheme.

Aims: This study aims to investigate the safety and efficacy of hMSC exosomes as a novel topical treatment for sensitive skin.

Patients/Methods: Exosomes were extracted from primary hMSC via ultracentrifugation method. The morphology of hMSC exosomes was studied via transmission electron microscope. Expression of exosome specific surface marker was detected via Western blot. 22 subjects (female, aged 18–55) diagnosed with sensitive skin were enrolled. Follow-up was conducted before, 7-day, 14-day, and 28-day after hMSC exosomes use. Transepidermal water loss (TEWL), surface hydration, sebum secretion, and L*a*b* value were simultaneously tested at the same time point in an environment-controlled room.

Results: Under transmission electron microscopy, the extracted hMSC exosomes were circular or elliptical with intact membrane structure, and their diameters ranged mainly from 40 to 80 nm. Western blot showed that the expression of markers CD63, CD9, and Tsg101 was positive. Brownian motion based nanoparticle trajectory analysis (NTA) showed that the main peak of particle size distribution occurred around 96 nm, the average particle size was 122 nm, and the main peak accounted for 96.7%. All this conformed to the biological characteristics of exosomes standardized by the International Society for Extracellular Vesicles. In the clinical trial, scores of objective symptoms including roughness, scales, erythema, and subjective symptoms including tension, burning, or itching, were improved after 7-, 14-, and 28- day using hMSC-exosomes. TEWL, hydration, sebum, pH, and a* values were tended to return to the level of healthy skin.

Conclusion: The hMSC-exosomes, with the advantages of biocompatibility and biodegradability, could improve clinical symptoms and eruptions in sensitive skin patients, and might be as an MSC cell-free novel therapy in sensitive skin-related disease treatment.

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.

Unbearable transepidermal water loss (TEWL) experimental variability: why?

Despite the wide breadth of research, much disparity exists in transepidermal water loss (TEWL) research data-possibly due to uncontrolled experimental variables. We determined whether such experimental variables significantly impact TEWL studies and cause this disparity. An initial literature search regarding TEWL was performed to determine potential confounding variables. A subsequent search procured relevant and representative studies investigating the impact of these variables on TEWL. Variables, such as age, anatomic site, and temperature, impact TEWL and should be controlled for in TEWL studies. Other variables, such as smoking and menstrual cycle, have inconclusive results or do not provide sufficient data breadth to make a conclusion regarding its effect, if such an effect exists, on TEWL metrics. Therefore, these variables require further research to determine their potential impact on TEWL. Matching for as many experimental variables as possible may reduce the disparity in TEWL data/conclusions.

Rosacea in acne vulgaris patients: Subtype distribution and triggers assessment-A cross-sectional study

BACKGROUND

Recent studies have reported that the incidence of acne combined with rosacea is increasing. However, the clinical feature and inducing factor of these two diseases co-occurrence is remain unclear.

AIMS

This study aims to investigate the classification and severity of female patients combining with acne and rosacea.

PATIENTS/METHODS

Female patients with facial acne combined with rosacea, 15-50 years old, were included from dermatology outpatient department from January 2019 to December 2019. The severity of acne was classified according to the Pillsbury grading system. Rosacea was diagnosed and classified according to the Standard issued by National Rosacea Society Expert Committee. Questionnaire was designed to collect the information of rosacea triggers from each patient.

RESULTS

563 vulgaris acne combined with rosacea patients (mean age 23.2 ± 43), included 70.33% severe acne (n = 396), 15.81% moderate acne(n = 89), and 13.85% mild acne(n = 78), had finished the study. In severe acne group, 72.47% combine with erythematotelangiectatic rosacea (ETR), 22.47% combined with papulopustular rosacea (PPR), and 5.05% combine with phymatous rosacea (PHR). In moderate acne group, 53.93% combine with ETR, 43.82% combined with papulopustular rosacea (PPR), and 2.24% combine with PHR. All patients in moderate acne subject group was combined with ETR (100%). Patients that did not use skin care produces presented 12.79 times higher rate to combine with ETR than that frequently using skin care products (P = .014).

CONCLUSIONS

Erythema telangiectasia rosacea is the most common rosacea type in female acne patients. There is a need to be vigilant about the combination of sever/moderate acne and papulopustular rosacea. Rational daily use of skin care products can reduce the incidence of rosacea in acne patients. For acne patients without family history of rosacea, dermatologists should also not ignore the healthy education to avoid potential triggers of rosacea.

Seasonal variations in the skin parameters of Caucasian women from Central Europe

BACKGROUND

The human skin is greatly affected by external factors such as UV radiation (UVR), ambient temperature (T), and air humidity. These factors oscillate during the year giving rise to the seasonal variations in the skin properties. The aim of this study was to evaluate the effect of seasons, environmental T, relative and absolute humidity on the skin parameters of Caucasian women, perform a literature review and discuss the possible factors lying behind the found changes.

MATERIALS AND METHODS

We measured stratum corneum (SC) hydration, transepidermal water loss (TEWL), sebum level, erythema index, and elasticity parameters R2 and R7 on the forehead and the cheek of Caucasian women from the Czech Republic throughout the year. We also performed a non-systematic literature review focused on the seasonal variations in these skin parameters.

RESULTS

We confirmed a well-documented low SC hydration and sebum production in winter. In spring, we found the lowest TEWL (on the forehead) and the highest SC hydration but also the highest erythema index and the lowest elasticity presumably indicating skin photodamage. For most of the skin parameters, the seasonal variations probably arise due to a complex action of different factors as we extensively discussed.

CONCLUSION

The data about the seasonal variations in the skin parameters are still highly inconsistent and further studies are needed for better understanding of the normal skin changes throughout the year.

Skin barrier damaging and repairing process: A new application field of dermoscopy

BACKGROUND

Although more and more noninvasive detection technologies have been used in assessing skin barrier integrity and functions, more accurate, intuitive, and convenient detective methods still needed to be explored and developed.

AIMS

To investigate the characteristic image changes under the dermoscopy and to explore the relationship with skin physiological indexes in skin barrier damaging and repairing process.

PATIENTS/METHODS

25 healthy subjects with normal skin in forearm were included and divided into different groups according to the operated strips numbers (30, 35, and 40 times). Before tape stripping, and immediately, 3, 7, 14, and 21 days after tape stripping, dermoscopic examination and skin transepidermal water loss (TEWL), surface hydration, and L*a*b* value were simultaneously tested in the same region.

RESULTS

Immediately after different times tape stripping, the amount of cuticle cells residues and the microvascular images were different. In skin barrier repairing process, the scab forming time observed under dermoscopy was day 14, day 7, and day 3 on 30 times, 35 times, and 40 times stripped skin, respectively. A small amount of cuticle cells and blurry vessels could be identified in hydration value <40 group, while there was no cuticle cell residue, and the branching vessels were obvious in hydration value >40 group.

CONCLUSIONS

Unique manifestations could be observed under dermoscopy in different time points of skin barrier with various degree of injury and in skin barrier repairing process. By combining dermoscopy and skin indexes assessing technologies, the skin barrier integrity and function could be observed and evaluated more accurately and precisely.