Development and Validation of a Comprehensive Acne Severity Scale

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.

Development and Validation of a Comprehensive Acne Severity Scale Journal Articles