L

L. Vaillant

Université de Tours

Publishes on Autoimmune Bullous Skin Diseases, Lymphatic System and Diseases, Cutaneous lymphoproliferative disorders research. 254 papers and 5k citations.

254Publications
5kTotal Citations

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Top publicationsby citations

Risk factors for erysipelas of the leg (cellulitis): case-control study
Cited by 574Open Access

OBJECTIVE: To assess risk factors for erysipelas of the leg (cellulitis). DESIGN: Case-control study. SETTING: 7 hospital centres in France. SUBJECTS: 167 patients admitted to hospital for erysipelas of the leg and 294 controls. RESULTS: In multivariate analysis, a disruption of the cutaneous barrier (leg ulcer, wound, fissurated toe-web intertrigo, pressure ulcer, or leg dermatosis) (odds ratio 23.8, 95% confidence interval 10.7 to 52.5), lymphoedema (71.2, 5.6 to 908), venous insufficiency (2.9, 1.0 to 8.7), leg oedema (2.5, 1.2 to 5.1) and being overweight (2.0, 1.1 to 3.7) were independently associated with erysipelas of the leg. No association was observed with diabetes, alcohol, or smoking. Population attributable risk for toe-web intertrigo was 61%. CONCLUSION: This first case-control study highlights the major role of local risk factors (mainly lymphoedema and site of entry) in erysipelas of the leg. From a public health perspective, detecting and treating toe-web intertrigo should be evaluated in the secondary prevention of erysipelas of the leg.

In vivo model of the mechanical properties of the human skin under suction
S. Diridollou, F. Patat, F. Gens et al.|Skin Research and Technology|2000
Cited by 335Open Access

BACKGROUND/AIMS: A new method for the in vivo characterization of the mechanical properties of skin has been developed. This comprises a suction chamber and an ultrasound device to measure both the vertical displacement of the skin's surface, and the skin's thickness. METHODS: A mathematical model of the mechanical behaviour of a taught elastic membrane is used to obtain a set of parameters intrinsic to the skin, such as Young's modulus (E) and the initial stress (sigma0), which reflect the stiffness and the natural tension of the skin, respectively. We also calculated an index of non-elasticity of the skin (unrestored energy ratio, UER), which takes into account the volume of tissue mobilized. It determines a ratio between the energy input to the skin and the energy it dissipates. These parameters were evaluated from the volar forearm of 10 normal male volunteers. RESULTS: The results were: 129+/-88 kPa for E, 13.5+/-5 kPa for sigma0, and 0.42+/-0.04 for UER; with reproducibilities of 9.5%, 12.4% and 6.4%, respectively. CONCLUSIONS: This new suction device was found useful for the study of the behaviour of the skin, and the device may be used for the evaluation of certain skin diseases and their therapy.

Transformation of mycosis fungoides: clinicopathological and prognostic features of 45 cases. French Study Group of Cutaneious Lymphomas.
Cited by 267

The course of mycosis fungoides (MF) is indolent except when transformation to a large T-cell lymphoma occurs. The diagnosis of transformed MF (T-MF) relies on the presence of more than 25% of large cells on biopsy of an MF lesion. We analyzed 45 patients with T-MF recorded by the French Study Group on Cutaneous Lymphomas to better determine clinicopathological features of MF transformation and to analyze their impact on prognosis. Median time from diagnosis of MF to transformation was 6.5 years. Extracutaneous progression was present in 20 patients. Mean survival from transformation to death was 22 months. In univariate analysis, only an extracutaneous progression was associated with a worse prognosis (5-year actuarial survival: 7.8% versus 32%). Neither sex, age, clinical and skin disease stage at transformation, transformation speed, nor percentage of large cells or CD30 expression (14 of 45) had a prognostic value. When performing multivariate analysis, age (at least 60 years), and extracutaneous spreading were found to be associated with a poor prognosis. There was no difference between survival curves of patients with T-MF and with pleomorphic large T-cell CD30- lymphomas. The main diagnostic pitfall was "histiocytic-rich" MF, requiring CD68 staining for the diagnosis of T-MF. Out of 45 patients, 6 presented an histologic transformation before clinical progression, suggesting that an early histopathological diagnosis may be performed by histological follow-up. The prognostic value of such early histopathological diagnosis must be confirmed by prospective studies.

Evaluation of Clinical Criteria for Diagnosis of Bullous Pemphigoid
L. Vaillant|Archives of Dermatology|1998
Cited by 194

OBJECTIVE: To check the potential usefulness of clinical criteria for the diagnosis of bullous pemphigoid when state-of-the-art techniques such as Western immunoblotting, immunoprecipitation, and indirect immunofluorescence on salt-split skin or direct immunoelectron microscopy are not available. DESIGN: Comparison of the clinical criteria between 2 groups (with and without bullous pemphigoid) as defined by immunoelectron microscopy used as standard criterion, in a prospective study. Multivariate logistic regression analysis was carried out by including all items that were statistically significant (at P < .05 level) in univariate analysis. SETTING: Five dermatology departments in teaching hospitals. PATIENTS: The 231 patients studied had subepidermal autoimmune bullous diseases with linear IgG or C3 deposits in the basement membrane zone (157 with bullous pemphigoid, 33 with cicatricial pemphigoid, 30 with epidermolysis bullous acquisita, 5 with lupus erythematosus, and 6 others). A second set of patients was used to calculate predictive values. RESULTS: The multivariate logistic stepwise analysis resulted in a final set of predictors that included only 4 items: absence of atrophic scars, absence of head and neck involvement, absence of mucosal involvement, and age greater than 70 years. No additional variables met the .05 significance level to enter into the model. If 3 of these 4 characteristics were present, a diagnosis of bullous pemphigoid could be made with a sensitivity of 90% and a specificity of 83%; these predictive values were calculated on a sample of 70 new cases. CONCLUSIONS: With and estimated incidence of bullous pemphigoid among subepidermal autoimmune bullous diseases of 80%, the presence of 3 of the 4 significant criteria allows the diagnosis of bullous pemphigoid, with a positive predictive value of 95%. Our set of clinical criteria thus allows the diagnosis of bullous pemphigoid with good validity for both clinical practice and therapeutic trials.

Does Hormonal Skin Aging Exist? A Study of the Influence of Different Hormone Therapy Regimens on the Skin of Postmenopausal Women Using Non-Invasive Measurement Techniques
A. Caliens, L. Vaillant, Philippe Lecomte et al.|Dermatology|2009
Cited by 183

BACKGROUND AND DESIGN: The skin properties of 98 postmenopausal women with hormone replacement therapy (oestradiol gel or patches) or without hormone replacement therapy were studied using non-invasive techniques: skin thickness with skin echography, skin hydration with a dryness score and measurement of capacitance, skin surface lipids with a Sebumeter and microtopography with image analysis of cutaneous replicas. RESULTS: In this open study we demonstrated an increase in skin thickness and sebum in the treated group in comparison to the untreated group (7-15% according to area for skin thickness, 35% for sebum). Hydration and microtopography were not different in the two groups. CONCLUSIONS: Postmenopausal women who were receiving hormonal substitution have a greater thickness and casual level than untreated women. We therefore suggest that hormonal aging exists and that cutaneous atrophy can be prevented with hormone replacement therapy.