Syndrome d'ehlers-danlos de type hypermobile : Une atteinte multi-systémique : Apport de l'ultrastructure cutanée pour une prise en charge personnalisée

Ehlers-Danlos syndrome (EDS) represents a heterogeneous group of disorders of the connective tissue structure. Currently, several types are distinguished following a limited set of clinical signs and genetic mutations. However, there is a lack of specificity of most recognized genetic alterations with the current clinical typing. In addition, the criteria from dermatopathology, ultrastructure and biomechanics are not considered. In addition, the established EDS frontiers are hazardous because a series of anatomo-clinical signs are not considered in the classical EDS concept. The hypermobile type EDS represents an example of the diagnostic uncertainties. It results that guidelines based on evidence-based medicine cannot be established. Only an individual management can be offered to the concerned patients

In vivo skin fluorescence imaging in young Caucasian adults with early malignant melanomas

Gérald E Piérard,1 Trinh Hermanns-Lê,2 Sébastien L Piérard,3 Lucas Dewalque,4 Corinne Charlier,4 Claudine Piérard-Franchimont,2 Philippe Delvenne2 1Laboratory of Skin Bioengineering and Imaging (LABIC), Department of Clinical Sciences, Liège University, 2Department of Dermatopathology, Unilab Lg, University Hospital of Liège, 3INTELSIG Laboratory, Montefiore Institute, University of Liège, 4Department of Clinical, Forensic and Environmental Toxicology, University Hospital of Liège, Liège, Belgium Background: Human cutaneous malignant melanoma (CMM) is an aggressive cancer showing a dramatic worldwide increase in incidence over the past few decades. The most prominent relative epidemiological increase has been disclosed in young women. The aim of the study was to assess the effects of chronic sun exposures in order to rate the extend of melanocytic stimulations in the vicinity of CMM. Methods: The study was designed to evaluate the melanin distribution and density using ultraviolet light illumination. The present study was performed on surgical excision specimens of thin CMM lesion removed from the upper limbs of 55 Caucasian adults (37 women and 18 men). Two control groups comprised 23 men and 21 women of similar ages who had medium-size congenital melanocytic nevi, also present on the upper limbs. The peritumoral skin was scrutinized using a Visioscan® VC98 device, revealing the faint mosaic melanoderma (FMM) pattern that grossly indicates early signs of chronic photodamage in epidermal melanin units. Results: The median extent of relative FMM was significantly higher in the CMM male group. By contrast, the CMM female group showed a reverse bimodal distribution in FMM size. Only 12/37 (32.5%) of the CMM female group had an increased FMM size, whereas 25/37 (67.5%) of females with CMM had a global FMM extent in the normal range, relative to the controls. Conclusion: Thin CMM supervening in young women appear unrelated to repeat photoexposure. Other mechanisms are possibly involved. Keywords: gender, HOX gene, ULEV method, genotoxicity, faint mosaic melanoderm

Age- and Body Mass Index-Related Changes in Cutaneous Shear Wave Velocity

BACKGROUND: The in vivo visco-elastic characteristics of skin depend on a series of physiopathological parameters. Among them, the age-related intrinsic tensile properties and the preconditioning of the tissues set under tension by the hypodermal volume might be of importance. AIMS: To revisit the influence of age and body mass on the firmness and mechanical anisotropy of the skin as determined by the velocity of the shear wave propagation. METHOD: Resonance running time measurements (RRTM) were performed on the mid volar forearm in 110 adults of both sexes. In each subject 16 RRTM were collected at four different precise angles with regard to the limb axis. We recorded the lowest, the highest and the mean multidirectional RRTM as well as the coefficient of variation (CV) of the latter value. In addition, the body mass index (BMI) was calculated. RESULTS: Age and BMI did not influence the minimum RRTM. In contrast, the maximum RRTM as well as the mean and CV of the multidirectional RRTM, significantly rose in a progressively increasing proportion of the subjects older than 60 years. These changes were only encountered in subjects with a normal BMI ranging from 18 to 25. Sex-related differences were not disclosed. CONCLUSIONS: The intrinsic skin tension lines identified by the minimum RRTM are not significantly altered with age and BMI variations. In contrast, skin laxity identified by larger maximum and mean multidirectional RRTM may increase after 60 years of age in subjects with a normal BMI. This is accompanied by increased skin mechanical anisotropy identified by CV values of the multidirectional RRTM over 40%

Pitted keratolysis: new ultrastructural insight in keratohyalin granule and corneodesmosome alterations.

Background: Pitted keratolysis (PK) is a superficial cutaneous infection caused by different species of bacteria. It is characterized by discrete crateriform and malodorous pits and erosions coalescing to form bizarre figures on the soles. Objective: To investigate the process of corneocyte shedding in PK. Method: Biopsies from typical lesions of three patients were investigated by transmission electron microscopy. Results: Microorganisms were found both inter- and intracellularly in corneocytes and keratinocytes of the upper layers of the stratum spinosum. Bacteria exhibited different morphologic aspects related to their localisation in the epidermis. Keratohyalin granules were strikingly abnormal, showing sharp segregation between rounded dense areas and more electron-translucent areas. Some keratohyalin granules exhibited only alveolar dense areas. These altered keratohyalin granules were still present inside corneocytes. The corneodesmosomes at the bottom of the pits were in part cleaved leading to partial corneocyte dissociation. Conclusion: It is suggested that proteases secreted by the bacteria alter the structure of both the corneodesmosomes and the keratohyalin granules. The latter appeared more resistant to the normal processing of profilaggrin inside the corneocytes