Cellulite, sometimes called gynoid lipodystrophy, is much more prevalent in women than in men. There are glaring discrepancies regarding the microanatomical descriptions of this condition in the literature. A lumpy aspect of the dermo-hypodermal interface is often cited, but it appears to represent a gender-linked characteristic of the thighs and buttocks without being a specific sign of cellulite. Incipient cellulite recognized by a discrete padded look or 'orange peel' aspect appears correlated with the presence of a network of focally enlarged fibrosclerotic strands partitioning the hypodermis and serving as a physiological buttress limiting the outpouching of fat lobules on pinching the skin. These connective tissue structures might represent a hormonal-dependent reactive process to sustained mechanical tensions caused by the adipocyte lobules. Full blown cellulite is recognized by a lumpy-bumpy and dimpled skin surface. It likely represents subjugation of the hypertrophic response of the hypodermal connective tissue strands when their resistance is overcome by progressive fat accumulation. In these cases, histological aspects reminiscent of striae distensae are identified within the hypodermal connective tissue strands. The mechanical properties of skin involved by cellulite process are altered, but may tend to resume to normal under treatment. These functional changes influence the mechanobiology of connective tissue cells, in particular the Factor XIIIa-positive dermal dendrocytes.

Skin capacitance imaging is a non-invasive, non-optical method that distinguishes three contrasting levels of stratum corneum hydration in psoriatic lesions. The lowest capacitance level probably corresponded to xerotic orthokeratosis. The medium capacitance level presumably identified foci of parakeratosis and clumps of neutrophils. The highest capacitance level suggested exsudation at the site of prominent vessel dilation and dermal inflammation. Impaired sweating in the psoriatic lesions may potentially interfere with body thermoregulation.

Two clinical studies were conducted to evaluate the tolerance and effects of a copolymer of chitin and beta-glucan, forming the exoskeleton of fungal cell walls, now supplied for cosmetic applications. A 6-week randomized, double-blind, placebo-controlled study was conducted on 13 volunteers with sensitive skin to compare with 0.5-2% formulations chitin-glucan applied twice daily. Biometrological evaluations showed that erythema did not develop, the water retention capacity of the stratum corneum increased and the transepidermal water loss moderately decreased. Another 16-week randomized, double-blind, placebo-controlled study was conducted on 20 men showing signs of ageing skin. A 1.5% chitin-glucan formulation was applied twice daily. Objective biometrological assessments showed a progressive increase in skin firmness and stratum corneum hydration when desquamation and skin roughness decreased. In conclusion, the chitin-glucan formulations appear safe. They significantly mitigate some signs of skin ageing and improve both stratum corneum hydration and skin barrier function.

The assessment of cosmetic efficacy is rarely performed in studies comparing different concentrations of active compounds. The aim of the present study was to determine the skin hydrating and the skin firming dose-response effects of cosmetic formulations enriched in compounds derived from algae and fish collagen. A series of factors were studied including the type of formulation (cream or serum), the concentration in active ingredients, the effect of repetitive applications, as well as any residual effect of the formulations after stopping their applications. The serum enriched in marine compounds showed a better moisturizing effect in short term. The cream appeared more active later, particularly following repeat applications. A sustained tensor (firming) effect was observed during treatment with both the lotion and the cream. However, no remnant firming effect was perceived after stopping treatment.

In diabetic neuropathy, the compensatory hyperhidrosis is more easily disclosed than the hypohidrosis. ACH affects both sweat excretion and the SC hydration.