Development and Validation of a Comprehensive Acne Severity Scale Journal Articles uri icon

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  • Background: Although more than 25 acne grading systems exist, only 2 are inclusive of truncal acne. There is neither a gold standard nor a consistently used standardized system. Purpose: Our purpose was to develop and validate an acne grading system incorporating severity at the face, chest, and back. Methods: We developed a comprehensive acne severity scale (CASS) by modifying a preexisting facial acne scale, the Investigator Global Assessment, to include truncal acne. The validity and responsiveness of CASS grades were correlated with Leeds scores at baseline and after 6 months of standard acne treatment. Results: Spearman correlations were significant between Leeds and CASS grades for the face (0.823), chest (0.854), and back (0.872), respectively ( p < .001). After 6 months of therapy, changes in these scores were also significantly correlated ( p < .001) at all three sites. Conclusion: Concurrent validity of CASS is demonstrated by a very strong correlation with Leeds grading. CASS is simpler to use than the Leeds system and more appropriate for translation of research trial results to clinical practice.


  • Tan, Jerry KL
  • Tang, Jing
  • Fung, Karen
  • Gupta, Aditya K
  • Thomas, D Richard
  • Sapra, Sheetal
  • Lynde, Charles
  • Poulin, Yves
  • Gulliver, Wayne
  • Sebaldt, Rolf

publication date

  • November 2007