Claudine Pierard-Franchimont

Effect of Hormone Replacement Therapy for Menopause on the Mechanical Properties of Skin

OBJECTIVE: To evaluate the effect of hormone replacement therapy (HRT) for menopause on the mechanical properties of the skin in healthy women.

Cellulite : From standing fat herniation to hypodermal stretch marks

There are glaring discrepancies in the microanatomical descriptions of cellulite in the literature. We revisited this common skin condition in women with a microscopic examination of 39 autopsy specimens. A control group consisted of 4 women and 11 men showing no evidence of cellulite. The lumpy aspect of the dermohypodermal interface appeared to represent a gender-linked characteristic of the thighs and buttocks without being a specific sign of cellulite. Incipient cellulite identified by the mattress phenomenon was related to the presence of focally enlarged fibrosclerotic strands partitioning the subcutis. Such strands possibly serve as a physiologic buttress against fat herniation limiting the outpouching of fat lobules on pinching the skin. These structures might represent a reactive process to sustained hypodermal pressure caused by fat accumulation. Full-blown cellulite likely represents subjugation of the hypertrophic response when connective tissue is overcome by progressive fat accumulation. Histologic aspects reminiscent of stretch marks are identified within the hypodermal strands, resulting in clinical skin dimpling.

EEMCO Guidance for the in vivo Assessment of Skin Greasiness

Sebaceous gland activity has four distinct components which are sebum production (a secretion rate function), storage (a volume function), surface output (a delivery rate function) and stratum corneum permeation (an influx rate function). The oily appearance of skin results from an excess of sebum excretion and spreading over the body surface and its interaction with the skin surface. A multi-pronged approach is often useful to assess skin greasiness with precision. The clinical evaluation of skin greasiness and its shiny appearance should be further complemented by quantifying the large pores, follicular plugs and comedones. The sebum amount present at the skin surface can be measured non-invasively using one of several methods based on solvent extraction, cigarette paper pads, photometric assessment, bentonite clay and lipid-sensitive tapes. Quantitative parameters include the sebum casual level, the sebum excretion rate, the sebum replacement time, the instant sebum delivery, the follicular excretion rate, the density in sebum-enriched reservoirs and the sustainable rate of sebum excretion. A series of environmental and biological features influence the data. Hence rigorous methodological designs are mandatory to support claims. As a rule, accuracy of the methods is adversely affected by skin temperature, degree of hydration and surface roughness. An additional confounding factor is the inherent difficulty of collecting the surface lipids without a contribution from the follicular reservoir. A better understanding of factors that alter the sebum amount at the skin surface may well assist in the development of sebosuppressive agents to help the reduction of the skin greasiness and improve acne.

Skin water-holding capacity and transdermal estrogen therapy for menopause: a pilot study

The effects of menopause and hormone replacement therapy (HRT) on the epidermis are largely unknown. The aim of this study was to model and measure the influence of estrogen-transdermal HRT on subtle physiological changes taking place in the epidermis during the perimenopause. Skin capacitance and transepidermal water loss were measured both on normal-looking skin and at the site of a plastic occlusion stress test (POST). Two groups of 15 menopausal women were enrolled. One group was untreated and the other received transdermal estrogen. The water-holding capacity of the stratum corneum was significantly increased at the POST site in women receiving transdermal estrogen. The improvement in the skin water-holding capacity, which is known to be associated with a beneficial effect on the skin barrier function, may contribute to the prevention of several dermatoses.

Influence of the Test Area on the Mechanical Properties of Skin

BACKGROUND New advances in bioengineering have provided commercially available devices for measuring the mechanical properties of skin in vivo. Reproducibility of data and methodological approaches have not yet been thoroughly studied. OBJECTIVE To study the reproducibility and the influence of the area of the test site on the values of biomechanical variables yielded in a normal population. METHOD A 500-mbar suction was transmitted to the skin through Cutometer probes equipped with a 2- or 8-mm opening. RESULTS The best reproducibility was obtained for the maximum distension of skin and for the biological elasticity. The values of the standard biomechanical ratios were almost the same for both probes. Linear correlations were found between parameters of elasticity. CONCLUSION The Cutometer is a reliable device. A high degree of correlation exists between biomechanical variables related to elasticity. Under a suction of 500 mbar, both the 2- and 8-mm probes give results which correlate statistically in a large population. However, the two probes do not measure precisely the same aspect of skin mechanics. The 2-mm probe measures the capacity of superficial skin folding, and the 8-mm probe explores the biomechanical properties of the dermis itself and of its slipping mobility on the hypodermis. The biomechanical parameters which appear the most clinically relevant for a normal-looking skin are the maximum distension and the biological elasticity.

Unraveling the Patterns of Subclinical Pheomelanin-Enriched Facial Hyperpigmentation: Effect of Depigmenting Agents

Background: During photoaging, the density of melanin chromatophores is heterogeneous in the epidermis. Aims: To define the patterns of pheomelanin-enriched melanotic hypermelanosis of the face in phototype II subjects and to assess the effect of depigmenting agents. Azelaic acid and glycolic acid were tested as well as a soy extract, reported to reduce pigmentation through interaction with the protease-activated receptor 2 (PAR-2) of keratinocytes. Method: Evaluations were made by image analysis of high magnification pictures obtained by a video camera equipped with an internal ultraviolet-emitting unit (Visioscan®). Results: Three patterns of subclinical facial hypermelanosis were recognized including the spotty perifollicular type, the accretive globular type and the elongated type of the sunny side of wrinkles. Azelaic acid and the soy extract led to significant skin lightening after a 3-week treatment. By contrast, glycolic acid showed an inconsistent effect. Conclusion: Sensitive fluorescence video recording combined with image analysis represents an advance in the noninvasive assessment of the mottled subclinical skin pigmentation. The depigmenting effect observed with the soy extract indicates that the inhibition of PAR-2 may be a novel way to approach certain pigmentary disorders of the skin.

The Beneficial Toxicity Paradox of Antimicrobials in Leg Ulcer Healing Impaired by a Polymicrobial Flora: A Proof-of-Concept Study

Background: Some of the views contrasting the beneficial and toxic effects of antimicrobials upon wound healing remain controversial. Objective: To assess the clinical relevance of histological findings following antimicrobial applications on chronic leg ulcers. Method: The present study was performed in three parallel groups of 17 patients suffering from at least 2 similar chronic leg ulcers. Clinical planimetric assessments were performed before and after 3 and 6 weeks of treatment using hydrocolloid dressings. In addition, 1 ulcer in each patient received applications of povidone-iodine (PVP-I), silver sulfadiazine or chlorhexidine digluconate. Histological examinations were made at inclusion and after the 6-week therapy. Time to healing was also recorded. Results: At entry in the study, fibroblasts, macrophages, neutrophils and vessels were abundant in the ulcers. In addition, focal necrotizing vasculitis was related to the microbiological load. Compared to the control lesions, both the healing rate and time to healing of the leg ulcers showed a modest improvement at the sites receiving silver sulfadiazine (2–7%) or chlorhexidine digluconate (–1 to 5%). By contrast, PVP-I increased significantly the healing rate (4–18%, p < 0.01), and time to healing was reduced by 2–9 weeks (p < 0.01). The 3 antimicrobials decreased the bacterial density, and the vascular margination and migration of inflammatory cells, thus abating the vasculitic changes. PVP-I applications did not alter the microvessels and did not significantly reduce the density in dendrocytes and fibroblasts. By contrast, both silver sulfadiazine and chorhexidine digluconate appeared to alter the superficial microsvasculature including the dendrocyte population. Conclusion: Although topical antimicrobials may apparently achieve almost similar activity on the bacterial load inside chronic leg ulcers, the toxicity upon host cells was different among these agents. PVP-I appeared to be an efficient compound in these respects exhibiting a positive and relevant clinical effect.

Dermal Ultrastructure in Low Beighton Score Members of 17 Families with Hypermobile-Type Ehlers-Danlos Syndrome

The distinction between the Ehlers-Danlos syndrome hypermobile type (EDSH) and the benign joint hypermobility syndrome (BJHS) is unclear. The aim of the present study was to compare skin ultrastructural abnormalities of EDSH and BJHS among different families. Skin of 23 EDSH, 27 BJHS, and 41 asymptomatic subjects from 17 families was examined using transmission electron microscopy. Similar ultrastructural abnormalities were found irrespective of the Beighton score. Flower-like collagen fibrils represented the key change and elastic fibers were altered as well. Beighton score is a clinical parameter rating joint mobility that appeared unrelated to quantitative and qualitative collagen ultrastructural alterations in the skin. Some EDSH family members fit with BJHS diagnosis. BJHS possibly represents a mild variant of EDSH.

Age-Related Changes in Facial Skin Contours and Rheology

OBJECTIVES: To evaluate the age effect on both the mechanical properties and wrinkling of facial skin. This topic has not previously been addressed in the literature.

Present and potential diagnostic techniques in onychomycosis

The problem of onychomycosis has been frequently addressed during recent years. To make the diagnosis of onychomycosis dermatologists have relied on clinical presentation, culture, and microscopy. These approaches are hampered by false-negative and false-positive results that have confused treatment outcomes. Two new diagnostic techniques, immunohistochemistry and flow cytometry, provide an effective means of identifying different dermatophytes, yeasts, and nondermatophytic molds. Immunohistochemistry employs antibodies to certain fungi to enable positive identification in situ, whereas flow cytometry differentiates fungi on the basis of molecular differences. These techniques provide new evidence that nondermatophytic molds and yeasts can actively invade nail tissue and that mixed infections occur. These findings could have important implications for the treatment of onychomycosis.