title: Does skin hydration influence keratinocyte biology? In vivo evaluation of microscopic skin changes induced by moisturizers by means of reflectance confocal microscopy.
abstract: BACKGROUND
  Skin hydration is defined as the water content of the epidermis and the dermis. In vivo reflectance confocal microscopy offers the opportunity to determine in vivo the kinetics of the skin after the application of topical products.
  
  
  OBJECTIVE
  To define confocal features associated with dry skin and assess the microscopic effects of different moisturizers.
  
  
  METHODS
  Ten healthy volunteers were enrolled for the study. Two different formulations were tested: petrolatum and a commercially available emulsion. Measurements were performed from baseline to 3 h after removal of the occlusion at regular time points. Nine confocal features were assessed: furrows' size, overall interkeratinocyte reflectance, furrows' morphology, scales, skin surface irregularity, non-rimmed dermal papillae, exocytosis, dermal inflammation and collagen type. Furrows' size and interkeratinocyte reflectance were also quantitated using a digital analysis. Stratum corneum capacitance was recorded.
  
  
  RESULTS
  At baseline, RCM showed the presence of micro-scales and high skin surface irregularity score. After the application of topical products, the scale score decreased significantly; Furrow's size and Digital Furrow's Size had a marked and directly correlated decrement. Furrow's morphology and Epidermal Irregularity scores decreased from baseline to 30 min, the latter reaching a plateau in product application areas. Interestingly, interkeratinocyte reflectance progressively increased with the application of the topical products, while remained stable in the control area, confirmed by Digital Interkeratinocytes reflectance quantitation.
  
  
  CONCLUSIONS
  RCM revealed that the changes involve the skin surface by reducing the micro-scales and epidermal irregularity. Even more interestingly, RCM showed that higher interkeratinocytes' brightness is seen for moisturizer, but not for the control area. This RCM finding could be linked to keratinocyte membrane protein exposure and/or substance release in the interkeratinocytic space. To sum up, RCM represents a useful imaging tool to analyze the morphologic changes at different time points following the application of topical products.
authors: Marco
authors: M
authors: Manfredini
authors: Department of Dermatology, University of Modena and Reggio Emilia, Italy.
authors: Manfredini
authors: M
authors: Marco
authors: Giovanna
authors: G
authors: Mazzaglia
authors: Mazzaglia
authors: M
authors: Giovanna
authors: Silvana
authors: S
authors: Ciardo
authors: Ciardo
authors: C
authors: Silvana
authors: Silvia
authors: S
authors: Simonazzi
authors: Simonazzi
authors: S
authors: Silvia
authors: Francesca
authors: F
authors: Farnetani
authors: Farnetani
authors: F
authors: Francesca
authors: Caterina
authors: C
authors: Longo
authors: Longo
authors: L
authors: Caterina
authors: Giovanni
authors: G
authors: Pellacani
authors: Pellacani
authors: P
authors: Giovanni
mesh_terms: D000287:Administration, Topical; D000328:Adult; D001834:Body Water / Q000378:metabolism; D046169:Dermoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology*; D063465:Skin Cream / Q000008:administration & dosage*; D016896:Treatment Outcome; D014870:Water Loss, Insensible / Q000187:drug effects / Q000502:physiology*
keywords: in vivo confocal microscopy; skin hydration