title: Measurement of actinic erythema in healthy subjects and in subjects with polymorphous light eruption using a tristimulus colorimeter.
abstract: BACKGROUND
  The assessment of actinic erythema using a tristimulus colorimeter has only been reported from healthy volunteers but never from subjects with photodermatosis.
  
  
  OBJECTIVE
  The aim of this study was to analyse the difference of chromometric measurements in patients with polymorphous light eruption versus healthy subjects.
  
  
  METHODS
  Seventy-two subjects were subdivided according to two criteria: skin colour and clinical state. Measurements were done on a non-irradiated site and at the clinical minimal erythema dose site in the L*, a* and b* modes.
  
  
  RESULTS
  The data submitted to two-way analysis of variance demonstrate the influence of skin colour and clinical state on the above parameters.
  
  
  CONCLUSIONS
  Chromometric measurements of L* help to differentiate skin colour, whereas those of a* enable the discrimination of healthy subjects from those with photodermatosis.
authors.affiliation: Faculté des Sciences Pharmaceutiques, Hôpital Purpan, Toulouse, France.
authors.forename: J
authors.initials: J
authors.lastname: Garigue
authors.forename: M C
authors.initials: MC
authors.lastname: Marguery
authors.forename: M F
authors.initials: MF
authors.lastname: Malmary
authors.forename: F
authors.initials: F
authors.lastname: el Sayed
authors.forename: J
authors.initials: J
authors.lastname: Bazex
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003124:Colorimetry / Q000295:instrumentation* / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D004890:Erythema / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D010787:Photosensitivity Disorders / Q000175:diagnosis* / Q000503:physiopathology; D012880:Skin Pigmentation / Q000528:radiation effects*; D014466:Ultraviolet Rays