title: Ethnic variations in facial skin neurosensitivity assessed by capsaicin detection thresholds.
abstract: BACKGROUND
  Ethnic variations in sensitive skin have not been thoroughly explored and remain controversial.
  
  
  OBJECTIVE
  To objectively assess ethnic variations in facial skin neurosensitivity through individual detection thresholds of topically applied capsaicin.
  
  
  METHODS
  The single-blind, controlled study was performed in 144 women from three ethnicities: Asian, African, and Caucasian. Five solutions with increasing capsaicin concentration were successively applied to one side of nasolabial folds, while the other side simultaneously received the vehicle as control. The test was discontinued when the volunteer reported on the capsaicin side a sensation whatever its nature. Otherwise the experimenter continued the test, using the next solution with higher capsaicin content and so on, until the subject experienced a sensation on the capsaicin side.
  
  
  RESULTS
  Each ethnic group was divided into six sub-groups according to the level of sensitivity to capsaicin, i.e. from detection of the lowest concentration up to no detection of the highest concentration, 100-fold higher. Asian women tended to have higher capsaicin detection thresholds than Caucasians, but lower thresholds than Africans. Nevertheless, the distribution did not greatly differ between the three ethnicities.
  
  
  CONCLUSIONS
  The capsaicin skin neurosensitivity test is painless and the changes across individuals of different ethnic backgrounds appear minimal.
authors.affiliation: L'Oreal Recherche, Centre Charles Zviak, 92583 Clichy cedex, France. rjourdain@rd.loreal.com
authors.forename: Roland
authors.initials: R
authors.lastname: Jourdain
authors.forename: Howard I
authors.initials: HI
authors.lastname: Maibach
authors.forename: Philippe
authors.initials: P
authors.lastname: Bastien
authors.forename: Olivier
authors.initials: O
authors.lastname: De Lacharrière
authors.forename: Lionel
authors.initials: L
authors.lastname: Breton
mesh_terms: D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D044466:Asian People; D044383:Black People; D002211:Capsaicin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005145:Face; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced* / Q000208:ethnology* / Q000503:physiopathology; D007509:Irritants / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology*; D016037:Single-Blind Method; D012867:Skin / Q000187:drug effects* / Q000294:innervation; D018709:Statistics, Nonparametric; D044465:White People
chemical_list: D007509:Irritants; D002211:Capsaicin