Jean-Marie Sainthillier

Age-Related Changes of the Cutaneous Microcirculation in vivo

Background: The architectural frameworks of the skin microcirculation are rather complex and change continuously with aging. But these changes are yet poorly documented in vivo. Objectives: Using non-invasive methods belonging to the field of biometrology, the study aimed to investigate quantitatively the changes of the cutaneous microvasculature in different anatomic sites with age. Methods: Measurements were performed on crow’s feet, forehead, volar forearm and dorsum of hand in 50 women (aged 20–74 years who consisted of 10 probands in each live decades). The superficial vascular plexus was scanned by videocapillaroscopy and assessed with the software Capilab Toolbox®. The subpapillary vascular plexus was explored with laser Doppler flowmetry. The skin color a* was analyzed by chromametry. Results: A marked site and age effect on the skin microcirculation has been demonstrated. The density of capillary loops in the eldest group decreased by about 40–70% compared with the youngest group whereas the vascular length increased by 35–156%. The capillary density in the back of the hand was 4 times higher than in the crow’s feet. The vascular length in the crow’s feet was 3 times longer than in the back of the hand. Both blood flow and skin redness (a*) increased also with age. Conclusion: Both morphology and quantification of the cutaneous microvasculature showed changes with site and age. Videocapillaroscopy associated to an image processing and laser Doppler flowmetry revealed different vascular layers. So the combination of both instruments offers an easy way to observe the architectural frameworks in vivo.

Assessment of cumulative exposure to UVA through the study of asymmetrical facial skin aging

Background: Published studies assessing whether asymmetrical facial ultraviolet light exposure leads to underlying differences in skin physiology and morphology report only clinical observations. The aim of this study was to assess the visual impact on the skin of repeated ultraviolet-A (UVA) exposure through a window. Methods: Eight women and two men presenting with asymmetrical signs of photoaging due to overexposure of one side of their face to the sun through a window over a long period of time were enrolled in the study. Split-face biometrologic assessments were performed (clinical scoring, hydration with Corneometer®, mechanical properties with Cutometer®, transepidermal water loss with AquaFlux®, skin relief with fringe projection, photography, stripping, and then lipid peroxidation analysis). Results: Significant differences were observed in clinical scores for wrinkles, skin roughness assessed by fringe projection on the cheek, and skin heterogeneity assessed with spectrocolorimetry on the cheekbone. Other differences were observed for skin hydration, as well as skin laxity, which tended towards significance. Discussion: This study suggests the potential benefit of daily UVA protection during nondeliberate exposure indoors as well as outside.

Capillaroscopy and videocapillaroscopy assessment of skin microcirculation: dermatologic and cosmetic approaches

Background  Different noninvasive bioengineering techniques exist to study the microvasculature of the skin and the dynamics of the microcirculation. The goal of these techniques is to visualize the skin capillary circulation easily and directly. Indeed, this information is irreplaceable to study the physiology and physiopathology of the skin capillary circulation efficiently.

Geometrical capillary network analysis

Background: Skin microcirculation, especially the superficial network, can be assessed by a computer capillary video microscope system. The study of morphology and dynamics of microcirculation must include all dynamic and cooperative processes between the capillaries. For characterizing capillary ensembles, the statistical and geometrical properties of the network need to be explored.

Skin capillary network recognition and analysis by means of neural algorithms

Background: The intra‐dermal capillary network can be easily assessed by a computerized videomicroscope system. Nevertheless, finding capillary loops automatically in an image is a difficult yet important first step in order to achieve microcirculation analysis.

Efficacy of micronutrient supplementation on skin aging and seasonal variation: a randomized, placebo-controlled, double-blind study.

Background Several studies have confirmed dramatic changes in skin surface parameters during the winter months. Although there are many studies supporting the positive effects of topical treatment, there are no published studies demonstrating the effects of oral supplementation in the prevention of negative skin changes during winter. The purpose of this study was to evaluate the efficacy of an oral micronutrient supplement in preventing the negative effects of winter weather on skin quality using noninvasive biometrologic instruments. Methods This study included 80 healthy female volunteers aged 35–55 years with phototype II–IV skin. Randomization was balanced. Two tablets of a micronutrient supplement (Perfectil® Platinum) or placebo were administered once daily for 4 months. The volunteers were examined at baseline, after 4 months, and 6 weeks after termination of treatment (month 5.5). The evaluation included skin microrelief by Visioscan® as the main outcome, and the secondary outcomes were results on standard macrophotography, skin tension by Reviscometer®, skin high-frequency ultrasound, and self-assessment. Results For all pseudoroughness and microrelief indicators, there was a significant increase from baseline to month 4 in the placebo group (P<0.05) but no change in the active group. Descriptive statistics for the mean minimum, mean maximum, and minimum to maximum ratio on the nonexposed study zone showed a significant and dramatic difference between baseline and month 4 and between baseline and month 5.5 (P<0.05) in the active group, indicating decreasing anisotropy of the skin. High-frequency ultrasound on the exposed study zone revealed that skin thickness was significantly decreased in the placebo group during winter but was stable in the treated group (P<0.01). The photography scaling and self-assessment questionnaire revealed no significant changes in either group. Conclusion These results indicate that the skin is prone to seasonal changes during winter, particularly in exposed areas. The data also indicate that oral supplementation can be a safe treatment, with no serious side effects, and may prevent or even eliminate the negative effects of winter on the skin.

Skin radiance: how to quantify? Validation of an optical method.

Background/purpose: The aim of this study was to validate an optic device used to measure the quantity of light reflected by the skin, which depends on the brightness of the skin.

Assessment of the efficacy and safety of a new treatment for head lice.

Infestation with head lice is a widespread, persistent, and recurring issue leading to serious health problems if untreated. We are facing resistance phenomena to usual pediculicides and questions about their direct or cumulative toxicity. The aim of this trial was to assess the efficacy of a new product, free of chemical insecticides but with a physical effect. This product contains components whose antilice efficacy has already been demonstrated, as well as Andiroba oil which asphyxiates the lice and Quassia vinegar which dissolves the chitin of the nits (they are then inactivated). 30 patients with head lice infestation, aged 3–39 years, applied the treatment one to three times, 5 days apart. Cure was defined as the absence of live lice after 5, 10, or 14 days, and symptoms are usually associated with infestation. Easiness and safety of the treatment were assessed by the patients and/or their parents. Overall cure rates were 20% on D5 after one treatment, 37% on D10 after two treatments, and 90% on D14 after three treatments. Symptoms such as itch, scalp dryness, redness, and flakiness rapidly diminished. This treatment seems to be a beneficial addition or a valuable alternative to existing treatments, considering the total absence of chemical insecticides, the absence of drug-resistance induction in head lice, the absence of major toxicological risks compared with usual pediculicides, and the favourable patient use instructions.

Development of a new sensor based on micro‐electro‐mechanical systems for objective in vivo measurement of the cutaneous temperature: application to foundations

Background/aims: The purpose of this work was to develop a new sensor for objective in vivo measurement of the cutaneous temperature based on micro‐electro‐mechanical systems (MEMS), and to compare these performances with those of a classical thermocouple. Research on this new sensor was carried out to allow the quantification of the thermal properties of the made‐up skin.

Exploratory study of the typology of various grades of mature skin

Post‐menopausal skin aging has intrinsic as well as extrinsic origins, and this process induces important disparities of appearance and feeling within an age range.