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Notes: We report a French pedigree with members having an inherited combination of non-epidermolytic palmoplantar keratoderma (NEPPK) and sensorineural deafness. The penetrance of both features was incomplete. Additional ectodermal defects were absent. The expression of numerous epidermal proteins (keratins, fillagrin, cornified envelope proteins, intercellular junction proteins including connexin 26, and loricrin) defined with immunolabelling was normal in the proband. The combination was shown to be associated with the A7445G point mutation in the mitochondrial genome (mtDNA). This mutation is responsible for a subtype of NEPPK which is so far the only mtDNA mutation-associated keratoderma.

Notes: We report a case of acute intoxication due to a massive overdose of isotrerinoin.A 29-year-old male patient ingested 900 mg of isotretinoin corresponding to 12·5mg (kg/day) or 30 times the prescribed dosage and 1 day later the patient experienced mild headache. Forty-eight hours later, cheilitis, diffuse cutaneous xerosis and desquamation of the forehead and of the external auditory meatus occurred; cutaneous xerosis and cheilitis resolved spontaneously. We determined the serum level of isotretinoin and of 4-oxo-isotretinoin, its natural metabolite in sera taken 4, 5, 6 and 11 days following ingestion.The side-effects were mild and represented only exacerbations of some common isotretinoin side-effects. To date, three other cases of isotretinoin overdosage have been reported. There was a low toxicity of isotreitnoin overdose.

Notes: We have investigated in vivo the change with age of various parameters that describe the physical properties of skin. The parameters were derived from pressure/displacement curves obtained by applying reduced pressure to a small area of skin and measuring the resulting displacement by 20 MHz scan echography. By fitting the pressure/displacement curves to a theoretical model, the following skin parameters were obtained: E, Young's modulus or stiffness (in Pascals); σ0, the initial stress (in Pascals); and the unrestored energy ratio (UER), an index related to cutaneous non-elasticity. These parameters, which are used in mechanics to define the intrinsic physical characteristics of materials, were measured for the first time on volar forearm skin of 206 male and female subjects, aged between 6 months and 90 years.The results showed that skin thickness increases until maturity and decreases for women over 50–60 years old, Young's modulus E increases linearly with age, and ageing is divided into two phases for natural stress, σ0 and the non-elasticity index UER. Natural stress σ0 increases until maturity and then rapidly decreases. The non-elasticity index decreases until puberty and steadily increases after puberty.This new procedure provides a simple quantitative assessment of the physical properties of the skin, revealing that the skin becomes thinner, stiffer, less tense and elastic with ageing.

Notes: Synopsis A new method for the in vivo characterization of the physical properties of skin is presented. This comprises an ultrasound device to measure the vertical displacement of the surface of the skin, as well as its thickness and that of the hypodermis under suction. In combination with this, a mathematical model is used to calculate the following skin parameters: Young’s modulus, the initial stress and an index of non-elasticity. These parameters were evaluated from the volar forearm and the forehead of 30 male and 30 females, of similar ages (28 ± 6-years-old).The sensitivity of the testing procedure, allowing the characterization of the mechanical parameters of the skin, easily differentiated these two sites, and in some cases, differences between women and men were demonstrated. The main results showed for both sexes that the thickness (P = 0.0001), Young’s modulus (P = 0.0001), and the index of non-elasticity (P = 0.0001) were greater for the forehead than for the ventral forearm, but that the initial stress was lower (P = 0.0001). The results show that the skin is thicker, stiffer and less tense and elastic on the forehead than on the ventral forearm, suggesting structural differences between these two sites (collagen fibre network, elastic fibres, epidermis, stratum corneum, microvascularization, actinic damage, presence of sebaceous glands, etc.).It is hoped that this device will be useful for the evaluation of certain skin disorders (scleroderma, Ehlers–Danlos syndrome, cutis laxa, oedema, etc.) and their therapy, as well as being a useful tool in skin ageing and cosmetic product assessment. Résumé Nous présentons un nouveau dispositif qui permet in vivo de caractériser les propriétés mécaniques de la peau. Ce système est composé d’une part, d’un appareillage ultrasonore qui permet de mesurer le déplacement vertical de la surface cutanée, et les épaisseurs de l’épiderme-derme et de l’hypoderme sollicités par une dépression, et d’autre part, d’un modèle biomécanique qui associe la peau à une membrane élastique tendue. Ce dispositif permet de déterminer l’épaisseur cutanée, le module d’Young, la contrainte initiale et un indice de non élasticité de la peau. Ces paramètres ont étéétudiés sur la face antérieure de l’avant-bras, et sur le front de deux groupes de 30 sujets des deux sexes et de même classe d’âge (28 ± 6 ans).La grande sensibilité de la méthode a permis de différencier nettement ces deux sites et dans certains cas de montrer des différences entre les femmes et les hommes. Les résultats les plus significatifs montrent pour les femmes comme pour les hommes, que l’épaisseur cutanée (P = 0.0001), le module d’Young (P = 0.0001), et l’indice de nonélasticité (P = 0.0001) sont plus importants sur le front que sur la face antérieure de l’avant-bras, alors que la contrainte initiale est plus faible (P = 0.0001). Ces résultats montrent que le tissu cutané sur le front est plus épais, plus raide, moins élastique et moins tendu que sur l’avant-bras face antérieure, suggérant des differences de structures (réseaux de fibres de collagène, fibres élastiques, épiderme, stratum corneum, micro-vascularisation…) entre ces deux sites.On espère maintenant, avec un tel dispositif étudier certaines pathologies cutanées (maladies scléreuses, syndrome d’Ehler–Danlos, cutis laxas, maladies oedemateuses, etc.), leur thérapie, le vieillissement cutané, et l’efficacité des produits cosmétiques.

Notes: The purpose of this study was to determine the frequency of contact allergy and photocontact allergy to sunscreens. A consecutive series of 54 patients with suspected clinical photosensitivity were assessed. All had the same standardized photobiological investigation from January 1989 to December 1990, including patch tests and photo patch tests with 6 sunscreen agents. Oxybenzone was found to cause 4 cases of allergic contact dermatitis (with photo aggravation in 2), and 3 cases of photocontact dermatitis (13% of patients). This is probably due to the wide distribution of oxybenzone in sunscreens and other cosmetics, 2 patients with polymorphic light eruption and persistent light reactivity, respectively, were regular sunscreen users. Photo biological investigation is necessary to ensure accurate diagnosis, since sunscreen contact or photo contact allergy may simulate other photosensitivity eruptions.

Notes: We have studied changes in the elasticity and viscosity of the skin in patients with lymphoedema, using a technique involving vertical extensibility by suction. We measured parameters which included immediate extensibility (Ue, which reflects the elastic properties of the skin), and delayed extensibility (Uv which reflects intracutaneous movements of a viscous type).In grade III lymphoedema, Ue is decreased and Uv is increased. These changes are explained by volume variations and histological alterations, and tend to normalize after treatment.Our study shows that measurement of extensibility is useful in evaluation of volume variations, effects of therapy, and disease evolution, as Ue variations correlate with volume variations and with Uv changes. This technique also provides information which is useful in assessing patiènts' functional difficulties in relation to skin infiltration, and might be of value in lymphoedema follow-up.