title: Seasonal and annual variation in the intensity of facial wrinkles.
abstract: OBJECTIVE
  We studied annual, seasonal and gender-dependent changes in the intensity of facial wrinkles.
  
  
  METHODS
  The study included 32 Japanese subjects (16 men, 16 women, aged 35-47). Wrinkles on the forehead, corner of the eye, lower eyelid and nasolabial groove of each subject were captured in photos and in replicas at 3-month intervals from March, 2009 to March, 2010. At each occasion, skin conductance in the stratum corneum and skin color were measured on the cheek. The photos obtained were used for visual scoring of wrinkle intensity, and the quantitative 3-D data of replicas were obtained.
  
  
  RESULTS
  An apparent annual variation in skin conductance, which is supposed to be caused by skin dryness, and in the level of skin brightness, which is supposed to be caused by sun tan, was found for both genders. In contrast, no seasonal changes were determined in wrinkle intensity. Three-D analysis revealed no annual variation in women but revealed annual variation in the depths of eye wrinkles in men.
  
  
  CONCLUSIONS
  There was a gender-dependent difference in the annual variation of wrinkle depth in subjects around 40 years of age. Seasonal environmental changes may affect on the eye wrinkles depth in men within a year.
authors: R&D Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi 321-3497, Japan. tsukahara.kazue@kao.co.jp
authors: Kazue
authors: K
authors: Tsukahara
authors: Osamu
authors: O
authors: Osanai
authors: Takashi
authors: T
authors: Kitahara
authors: Yoshinori
authors: Y
authors: Takema
mesh_terms: D000328:Adult; D001834:Body Water / Q000378:metabolism; D002610:Cheek / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012621:Seasons; D012680:Sensitivity and Specificity; D012737:Sex Factors; D012867:Skin / Q000033:anatomy & histology*; D012869:Skin Absorption / Q000502:physiology*; D015595:Skin Aging / Q000502:physiology*; D014870:Water Loss, Insensible / Q000502:physiology*
keywords: seasons; sex factors; skin color; skin conductance; wrinkle