Morphological, structural and biophysical properties of French and Brazilian photoaged skin.

BACKGROUND: Knowledge of skin biology and its alterations in different populations is very important for the development of appropriate skincare strategies. OBJECTIVES: To evaluate and compare morphological, structural and biophysical properties of photoaged skin in French and Brazilian populations, using biophysical and skin-imaging techniques. METHODS: Forty-one French and 41 Brazilian healthy, female volunteers aged between 40 and 65 years were enrolled. Each participant completed a questionnaire concerning habits related to cosmetic use, sun exposure and sun protection during different life periods. Skin on the face and volar forearm was evaluated using noninvasive techniques, to determine skin colour, transepidermal water loss (TEWL), stratum corneum water content, skin microrelief, skin viscoelasticity and dermis structure. Reflectance confocal microscopy was used to measure epidermal layer thickness and epidermal morphological and structural characteristics. RESULTS: Compared with Brazilian skin, French skin was more hydrated, had a lower TEWL and presented a distinct viscoelastic profile on the forearms and face. Brazilian facial skin was more wrinkled, and the dermis was less echogenic on the forearms and face. The French participants had thicker stratum corneum. Brazilian facial skin presented a higher prevalence of rete ridge effacement, low interkeratinocyte reflectance, huddled collagen and solar elastosis. CONCLUSIONS: Morphological, structural and biophysical differences were found when assessing the skin of the Brazilian and French participants, who were exposed to different environmental factors.

MC1R major variants are a risk factor of sleep lines in Caucasian women.

BACKGROUND: Sleep lines are caused by individual's sleeping positions and should be differentiated from expression wrinkles. OBJECTIVE: The aim of the study was to investigate possible risk factors for sleep lines on a sizeable sample of middle-aged Caucasian women. METHODS: This study involved a sample of 542 French middle-aged women (44 to 70 years old) from Paris area. Three standardized facial photographs (face and profiles) were examined independently by two dermatologists allowing the identification of sleep lines and the evaluation of the severity of several facial skin features. Possible impacts of MC1R gene polymorphisms were tested using logistic regression models. RESULTS: Sixty women (11%) had facial sleep lines and showed generally more than one sleep line. The sleep lines were often located on the forehead, along the nose, on the cheeks and under the eyes, and more rarely on the chin. As expected, the sleep lines were associated with age, and the women with sleep lines showed also more severe signs of skin ageing. After adjustment on possible confounders, the presence of two major diminished function variants of the MC1R gene was identified as a strong risk factor for sleep lines [adjusted odds ratios (AOR) (95% CI): 8.25 (2.62-25.97)]. DISCUSSION/CONCLUSION: The data in the literature are scarce and this study is the first to be conducted on a sizeable sample of women. Our results suggest that genetic variations of MC1R are important determinants of the development of sleep lines.

Influence of skin ageing features on Chinese women's perception of facial age and attractiveness.

OBJECTIVES: Ageing leads to characteristic changes in the appearance of facial skin. Among these changes, we can distinguish the skin topographic cues (skin sagging and wrinkles), the dark spots and the dark circles around the eyes. Although skin changes are similar in Caucasian and Chinese faces, the age of occurrence and the severity of age-related features differ between the two populations. Little is known about how the ageing of skin influences the perception of female faces in Chinese women. The aim of this study is to evaluate the contribution of the different age-related skin features to the perception of age and attractiveness in Chinese women. METHODS: Facial images of Caucasian women and Chinese women in their 60s were manipulated separately to reduce the following skin features: (i) skin sagging and wrinkles, (ii) dark spots and (iii) dark circles. Finally, all signs were reduced simultaneously (iv). Female Chinese participants were asked to estimate the age difference between the modified and original images and evaluate the attractiveness of modified and original faces. RESULTS: Chinese women perceived the Chinese faces as younger after the manipulation of dark spots than after the reduction in wrinkles/sagging, whereas they perceived the Caucasian faces as the youngest after the manipulation of wrinkles/sagging. Interestingly, Chinese women evaluated faces with reduced dark spots as being the most attractive whatever the origin of the face. The manipulation of dark circles contributed to making Caucasian and Chinese faces being perceived younger and more attractive than the original faces, although the effect was less pronounced than for the two other types of manipulation. CONCLUSION: This is the first study to have examined the influence of various age-related skin features on the facial age and attractiveness perception of Chinese women. The results highlight different contributions of dark spots, sagging/wrinkles and dark circles to their perception of Chinese and Caucasian faces.

Freckles and solar lentigines have different risk factors in Caucasian women.

BACKGROUND: To date, few epidemiological data on the relationships between solar lentigines, freckles and behavioural and constitutional risk factors in Caucasian populations exist. OBJECTIVES: To investigate the potential impact of behavioural and phenotypic variables, as well as the MC1R genetic background, on the history of facial freckles and the severity of solar lentigines in Caucasian women. METHODS: The severity of solar lentigines was graded from facial digital images of 523 French middle-aged women by a dermatologist and summarized by a score afterwards. The history of facial freckles was assessed and the sun-exposure behaviour was characterized using a six-category typology. Risk factors including MC1R polymorphism were evaluated using logistic regression models. RESULTS: Two constitutive host factors were found to be independently associated with a history of facial freckles: frequent sunburns and the presence of diminished function variants of the MC1R gene. In addition to age, five factors were independently associated with solar lentigines: constitutive host factors (dark skin colour and tanning capacity), a history of freckles, sun-exposure behaviour and current intake of oral contraceptive or progestogen treatments. CONCLUSION: These results strengthen the hypothesis that solar lentigines are markers of photoaging, whereas freckles are mainly determined by genetic factors. The finding that hormonal treatment is associated with a higher risk for solar lentigines merits further investigations.

Impact of filaggrin mutations on Raman spectra and biophysical properties of the stratum corneum in mild to moderate atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is associated with null mutations in the filaggrin (FLG) gene. OBJECTIVE: To assess the impact of FLG null mutations on biophysical properties and the molecular composition of the stratum corneum (SC) in healthy individuals and AD patients. METHODS: A total of 196 French adults, including 97 with a history of mild to moderate AD, were genotyped for the three major European FLG mutations. Components of the natural moisturizing factor (NMF), lipids and water content in the SC were determined using Raman spectroscopy. In addition, trans-epidermal water loss, capacitance and pH of the SC were measured. RESULTS: Stratum corneum concentrations of total NMF, water, ornithine and urocanic acid (UCA) were significantly lower in AD patients than in healthy controls. Null mutations of FLG were detected in 4% of controls and 10% of AD patients. FLG mutations were associated with increased SC levels of lactate, reduced concentrations of most other NMF components and higher disease severity in AD patients. In AD patients without FLG mutations, the content of NMF constituents decreased with increasing disease severity. The concomittant presence of low concentrations of histidine, alanine and either glycine or pyrrolidone-5-carboxylic acid (PCA) in the SC was associated with FLG mutations with 92% specificity. CONCLUSIONS: Our findings suggest a low prevalence of FLG mutations in mild AD and support an important role for filaggrin in determining the physicochemical parameters of the SC. The combined measurement of several filaggrin breakdown products in the SC may be useful to specifically predict the presence of FLG mutations.

[MC1R polymorphisms and facial photoaging]. / Polymorphismes du MC1R et photovieillissement du visage.

BACKGROUND: The objective of this study was to assess the association between melanocortin-1 receptor (MC1R) variants and the severity of facial skin photoaging. METHODS: The study population comprised 530 French middle-aged women between 44 and 70 years. A trained dermatologist graded the severity of facial skin photoaging from photographs using Larnier's global scale. Logistic regressions were performed to assess the influence of MC1R polymorphism on severe photoaging (grades 1-3 vs. 4-6), with adjustment for possible confounders (demographic and phenotypic data, and sun exposure intensity). RESULTS: Overall, 35% of the women were wild-type homozygotes, 49% had one variant, 15% had two variants, and 1% had at least one rare variant. After adjustment for possible confounders, the presence of two major diminished function variants was found to be a risk factor for photoaging (adjusted odds ratio=5.61; 95% confidence interval [1.43-21.96]). DISCUSSION: Our results suggest that genetic variations of MC1R are important determinants for severe photoaging.

Cervical occult spinal dysraphism: MRI findings and the value of a vascular birthmark.

Spinal dysraphism is easily recognized in the overt form as a meningocele or myelomeningocele. The closed form or occult spinal dysraphism (OSD) can be overlooked. It occurs predominantly at the lumbosacral level, but OSD at the cervical level, although very rare, also occurs. The value of magnetic resonance imaging investigations in preparation for surgical treatment is emphasized. We discuss the value of various midline posterior skin anomalies as indicators of an underlying developmental defect in the neural axis. Hallmarks for OSD in the inferior third of the back are well known. They can also occur at the cervical level. Among these warning cutaneous midline changes, a vascular stain alone is rarely a clue for OSD whatever the spinal level involved, and specifically in the nuchal area.