Parametric Acne Severity (PAS) Score and Lesion Counts From Multi-Modality Facial Image Analysis Correlates Strongly with Investigator Assessment

Variability in acne lesion counting and assessing global severity necessitates large sample sizes that increase trial costs. Lack of standardized measures for these outcomes precludes the conduct of meta-analyses needed to compare efficacy of acne treatments. The goal of this study was to evaluate objective measures of lesion counts and global severity using analysis of multimodal photography. An algorithm for counting lesions was trained and validated in 30 acne subjects and compared to parallel assessments by 2 expert raters. A composite of photographic data representative of acne lesion topography, erythema, and C Acnes fluorescence was used to generate a Parametric Acne Severity (PAS) score. No relationship was identified between lesion counts and IGA. The correlation coefficients between raters and the algorithm when compared per view for the inflammatory and non-inflammatory lesion counts were 0.77 (P=0.001) and 0.85 (P=0.001), respectively. The correlation coefficient between the raters’ IGA grades and the PAS score was 0.82 (P<0.05). These data demonstrate that the lesion counting, and PAS are objective measures that strongly correlate with investigator assessments. Inclusion of these measure in clinical trials may reduce variability, standardize outcomes, and provide insights into treatment effects on photographic parameters associated with acne. J Drugs Dermatol. 2021;20(6):642-647. doi:10.36849/JDD.6165.