title: Sensitive Skin: Assessment of the Skin Barrier Using Confocal Raman Microspectroscopy.
abstract: OBJECTIVE
  Sensitive skin (SS), a frequently reported condition in the Western world, has been suggested to be underlined by an impaired skin barrier. The aim of this study was to investigate the skin barrier molecular composition in SS subjects using confocal Raman microspectroscopy (CRS), and to compare it with that of non-SS (NSS) individuals as well as atopic dermatitis (AD) and allergic rhinoconjunctivitis (AR) subjects, who frequently report SS.
  
  
  METHODS
  Subjects with SS (n = 29), NSS (n = 30), AD (n = 11), and AR (n = 27) were included. Stratum corneum (SC) thickness, water, ceramides/fatty acids, and natural moisturizing factor (NMF) were measured by CRS along with transepidermal water loss and capacitance on the ventral forearm, thenar, and cheek. Sebum levels were additionally measured on the forearm and cheek.
  
  
  RESULTS
  No differences between SS and NSS subjects were found regarding SC thickness, water, and NMF content, yet a trend towards lower ceramides/fatty acids was observed in the cheek. Compared to AD subjects, the SS group showed higher ceramides/fatty acid content in the forearm, whereas no differences emerged with AR. The correlation of macroscopic biophysical techniques and CRS was weak, yet CRS confirmed the well-known lower content of NMF and water, and thinner SC in subjects with filaggrin mutations.
  
  
  CONCLUSIONS
  The skin barrier in SS is not impaired in terms of SC thickness, water, NMF, and ceramides/fatty acid content. The failure of biophysical techniques to follow alterations in the molecular composition of the skin barrier revealed by CRS emphasizes a strong need in sensitive and specific tools for in vivo skin barrier analysis.
authors.affiliation: Radboud Institute for Molecular Life Sciences (RIMLS), Nijmegen, The Netherlands.
authors.forename: Renée J H
authors.initials: RJ
authors.lastname: Richters
authors.forename: Denise
authors.initials: D
authors.lastname: Falcone
authors.forename: Natallia E
authors.initials: NE
authors.lastname: Uzunbajakava
authors.forename: Babu
authors.initials: B
authors.lastname: Varghese
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Caspers
authors.forename: Gerwin J
authors.initials: GJ
authors.lastname: Puppels
authors.forename: Piet E J
authors.initials: PE
authors.lastname: van Erp
authors.forename: Peter C M
authors.initials: PC
authors.lastname: van de Kerkhof
mesh_terms: D000293:Adolescent; D000328:Adult; D002518:Ceramides / Q000032:analysis; D003233:Conjunctivitis, Allergic / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D000091344:Filaggrin Proteins; D005990:Glycerol / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D065631:Rhinitis, Allergic / Q000378:metabolism; D012867:Skin / Q000737:chemistry / Q000378:metabolism*; D012869:Skin Absorption; D013059:Spectrum Analysis, Raman; D055815:Young Adult
chemical_list: D002518:Ceramides; C000717249:FLG protein, human; D005227:Fatty Acids; D000091344:Filaggrin Proteins; D005990:Glycerol