Skin surface hydration decreases rapidly during long distance flights.

Introduction: Dehydration of the stratum corneum leads to sensations and symptoms of 'dry skin' such as skin tightness and itchiness. As these complaints are frequently experienced by airline travellers, the aim of this study was to investigate the changes in skin surface hydration during long distance flights.

Methods: The study was performed on four healthy Caucasian, and on four Japanese women aged 29-39 years, travelling on long distance flights.

Variations of skin biophysical properties after recreational swimming.

Background/purpose: Sensations of itching and skin tightness are frequently reported after recreational swimming in pool water. Our objective was to measure the potential changes occurring at the skin surface under such conditions.

Methods: Nine women participated in this study, which consisted of two periods.

MC1R gene polymorphism affects skin color and phenotypic features related to sun sensitivity in a population of French adult women.

The melanocortin-1 receptor (MC1R) gene is known to play a major role in skin and hair pigmentation and to be highly polymorphic in Caucasians. This study was performed to investigate the relationships between MC1R gene polymorphisms and skin color in a large sample of French middle-aged Caucasian women. The codons 60 to 265 and the codon 294 of the MC1R gene were sequenced in 488 women.

Influence of skin colour on the detection of cutaneous erythema and tanning phenomena using reflectance spectrophotometry.

Background/purpose: This research aims at assessing the influence of baseline skin colour on the ability of reflectance spectrophotometry to detect cutaneous erythema induced by a low concentration of methyl nicotinate (2.5 mM) (first objective), and to detect tanning induced by ultraviolet rays (UVA+UVB) at infra-erythemal doses (second objective).

Methods: Two independent studies were conducted to reach their respective objectives, on 27 women for the first study and on 12 women for the second study.

Relationships between visual and tactile features and biophysical parameters in human facial skin.

Background/purpose: Skin properties, such as colour, hydration and texture, can be studied on a qualitative basis by a clinical assessment or on a quantitative basis using techniques that measure biophysical properties of the skin. The aim of this study was to explore the links between facial skin features and a range of skin biophysical parameters using multivariate methods.

Methods: A study was conducted on 256 female volunteers from Ile-de-France with apparent healthy skin, aged between 20 and 50, under controlled environmental conditions (mean+/-standard deviation: room temperature 22.