A Multidimensional Acne Global Grading System

Encoding Clinicians


Accurate and reproducible acne assessment is a challenging task. While dozens of severity scales exist, most focus exclusively either on lesion counting or on evidence of scarring. An optimal grading system should ideally model how dermatologists are able to rapidly form an opinion on the acne state. By analyzing how dermatologists evaluate acne in the clinic, we first created a multidimensional acne severity space and then reduced it to a more intuitive scale that can be used for clinical and research use, linking acne’s visual features to a severity that reflects primary lesions as well as overall acne activity, and in particular scarring.


Create an acne grading system to provide, upon a visual inspection only of an acne affected skin area, a severity level that may serve as an entry point for treatment.

The electronic form below allows you to try out the multidimensional acne scale presented in the paper. Anyone can use it to assess acne from a visual inspection as long as they are familiar with the basic definitions of acne lesions and how they appear (here is a quick overview of primary lesions from the AAD). Please note that the scale should be used as explained in the manuscript and is only meant for a non-commercial use. We also ask that you cite the paper below if you use the scale for any research purposes.

References: Bernardis E, Shou S, Barbieri, McMahon PJ, Perman, MJ, Rola LA, Streicher JL, Treat JR, Castelo-Soccio L, Yan AC, Development and Initial Validation of a Multidimensional Acne Global Grading System Integrating Primary Lesions and Secondary Changes, JAMA Dermatology, Jan. 2020. [paper]

Acknowledgments: Thanks to the Penn Libraries' Biomedical Library and the Library's Innovation Intern, James Bigbee, for the implementation of the severity scale interface.