title: The use of facial modeling and analysis to objectively quantify facial redness.
abstract: BACKGROUND
  The reproducible evaluation of facial redness is critical to the assessment of erythematotelangiectatic rosacea. Assessments have typically focused on the use of photography with the use of semi-quantitative grading scales based on evaluator rating. However, few studies have utilized computer-based algorithms to evaluate facial redness.
  
  
  OBJECTIVE
  The purpose of this clinical study was to assess whether there is correlation between clinical grading of facial redness to the assessment of a quantitative computer-based facial modeling and measurement.
  
  
  METHODS
  In this prospective study, a set of high-resolution facial photographs and cross-polarized subsurface photographs for erythema detection were obtained for 31 study participants. A computer algorithm was then utilized to detect and quantify facial redness in the photographs and compare this to semi-quantitative evaluator-based grading for facial redness.
  
  
  RESULTS
  There was a strong correlation between computer-based cross-polarized subsurface erythema quantification and clinical grading for redness intensity (Clinical Erythema Assessment), redness distribution, and overall redness severity (Modified Clinical Erythema Assessment).
  
  
  CONCLUSIONS
  Overall, facial redness measurements by facial imaging and computer analysis correlated well to clinical grading scales for both redness intensity and distribution. Future studies should incorporate facial modeling and analysis tools for assessments in clinical studies to introduce greater objectivity and quantitative analysis in facial erythema-based analyses.
authors.affiliation: Department of Dermatology, University of California - Davis, Sacramento, CA, USA.
authors.forename: Negar
authors.initials: N
authors.lastname: Foolad
authors.affiliation: Department of Dermatology, University of California - Davis, Sacramento, CA, USA.
authors.forename: Neha
authors.initials: N
authors.lastname: Prakash
authors.affiliation: Department of Dermatology, University of California - Davis, Sacramento, CA, USA.
authors.forename: Vivian Y
authors.initials: VY
authors.lastname: Shi
authors.affiliation: Department of Dermatology, University of California - Davis, Sacramento, CA, USA.
authors.forename: Faranak
authors.initials: F
authors.lastname: Kamangar
authors.affiliation: Department of Statistics, University of California - Davis, Davis, CA, USA.
authors.forename: Qinlu
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Division of Biostatistics, Department of Public Health Sciences, University of California - Davis, Sacramento, CA, USA.
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.affiliation: Department of Dermatology, University of California - Davis, Sacramento, CA, USA.
authors.forename: Raja K
authors.initials: RK
authors.lastname: Sivamani
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003198:Computer Simulation; D004890:Erythema / Q000000981:diagnostic imaging*; D005148:Facial Dermatoses / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010781:Photography; D012393:Rosacea / Q000000981:diagnostic imaging*; D012720:Severity of Illness Index
keywords: erythema; facial grading scale; imaging; photography; redness; rosacea