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.

Latent class analysis categorizes chronic hand eczema patients according to skin barrier impairment.

BACKGROUND: Chronic hand eczema (CHE) is the most common skin disorder affecting the hands. It causes major physical and psychological burden for patients. Classification of CHE remains challenging because of its aetiological and clinical heterogeneity. OBJECTIVES: Using latent class analysis (LCA) on a large categorical data set, our aim was to identify distinct phenotypes in a cohort of unselected CHE patients based upon clinical, genetic, molecular and physical parameters of the affected skin. METHODS: We performed two independent LCA on a cohort of 71 well-characterized patients that initially integrated clinical severity, total immunoglobulin E plasma level, transepidermal water loss, hydration index, interleukin(IL)-8 lesional skin level, Staphylococcus (aureus and epidermidis) colonization, FLG genotype and the expression (mRNA) of genes involved either in the filaggrin degradation and the natural moisturizing factor synthesis, the cornified envelope formation, the tight junctions' structure and the desquamation process, or encoding antimicrobial peptides and chemokines. RESULTS: The first LCA categorized patients into a group displaying high severity of CHE, high skin barrier impairment, high Staphylococcus colonization, high IL-8 skin level and high frequency of mutation in the FLG gene and a second group with opposite characteristics. The second LCA identified two independent groups of patients categorized by their low or high level of skin barrier impairment and corresponding changes in the expression of the related genes. CONCLUSIONS: Our study suggests that the degree of skin barrier dysfunction is the most important parameter to discriminate CHE patients and probably plays a pivotal role in the pathogenesis of the disease whatever the aetiological factors. As far as we know, this is the first study to address this topic using a statistical categorization method without preconception.

Protection against summer solar lentigo over-pigmentation with a SPF30 daily cream.

BACKGROUND/PURPOSE: The aim of this study was to measure lentigines' pigmentation over a long period of time and evaluate if summer over-pigmentation can be avoided by the use a SPF30 day skin cream. METHODS: Seventeen healthy female volunteers aged 50 and over and presenting lentigines participated in the study from spring to summer. Throughout the study, all subjects applied a SPF30 daily skin cream to only one hand. Color measurements of the target lesions were performed with a chromameter and with a color-calibrated camera. Target lesions were also imaged with in vivo reflectance confocal microscopy (RCM). A specific procedure for re-registering the images was developed to ensure that the same papillae were measured over time. RESULTS: Both color measurement methods, chromametry and color-calibrated camera, showed that lentigines treated over time with the SPF30 day skin cream were significantly lighter than the non-treated lentigines. The RCM images showed a decrease in the papillary contrast for the treated lentigines. CONCLUSION: This study shows that this over-pigmentation can be avoided using a SPF30 day skin cream. Moreover, we have demonstrated that very fine re-registration of the RCM images is possible and ensures a more robust analysis.

Green microparticles based on a chitosan/lactobionic acid/linoleic acid association. Characterisation and evaluation as a new carrier system for cosmetics.

The association chitosan/linoleic acid/lactobionic acid in aqueous solution spontaneously led to the formation of stable microparticles with a liquid hydrophobic core consisting of linoleic acid surrounded by a shell of chitosan/lactobionic acid. The originality of the microparticles arises from the fact that they are formed by the association of three ingredients of cosmetic interest, including a skin penetration enhancer (linoleic acid). Dynamic light scattering (DLS) measurements showed microparticles with a mean diameter of 1-2 µm. The presence of a hydrophobic liquid core was observed by transmission electron microscopy (TEM). The ability of these microparticles to encapsulate phenylethyl resorcinol, a hydrophobic skin lightener, was evaluated and its encapsulation was confirmed thanks to T2 measurements and nuclear Overhauser effects (nOe) signs.

Follow-up of solar lentigo depigmentation with a retinaldehyde-based cream by clinical evaluation and calibrated colour imaging.

BACKGROUND AND OBJECTIVE: To assess an objective method evaluating the effects of a retinaldehyde-based cream (RA-cream) on solar lentigines; 29 women randomly applied RA-cream on lentigines of one hand and a control cream on the other, once daily for 3 months. METHODS: A specific method enabling a reliable visualisation of the lesions was proposed, using high-magnification colour-calibrated camera imaging. Assessment was performed using clinical evaluation by Physician Global Assessment score and image analysis. Luminance determination on the numeric images was performed either on the basis of 5 independent expert's consensus borders or probability map analysis via an algorithm automatically detecting the pigmented area. RESULTS: Both image analysis methods showed a similar lightening of ΔL* = 2 after a 3-month treatment by RA-cream, in agreement with single-blind clinical evaluation. CONCLUSION: High-magnification colour-calibrated camera imaging combined with probability map analysis is a fast and precise method to follow lentigo depigmentation.