Development and validation of a Scale for Acne Scar Severity (SCAR-S) of the face and trunk

scarring is an important component of overall acne severity, but there are no global scales for its evaluation inclusive of the face and trunk.

our objective was to develop a global scale for acne scar severity inclusive of the trunk and the face.

a six-category global severity scale (SCAR-S) was developed for assessment of acne scarring at each of the face, chest, and back. We evaluated SCAR-S against acne severity and patient-reported scar severity.

of 973 subjects, 73% reported acne scarring. Self-assessment of scarring was associated with facial SCAR-S and overall SCAR-S scores (p < .001, r = .31 and .30, respectively). Acne scarring was observed at the face in 87%, the back in 51%, and the chest in 38%. Clinically relevant scarring (mild or greater) at each of these regions was 55%, 24%, and 14%, respectively. Acne severity correlated with SCAR-S (p < .001) for the back (r = .612), the chest (r = .548), and the face (r = .514). Acne duration correlated with patient-reported severity of scarring (r = .244) and overall SCAR-S scores (r = .152). Clinically relevant scarring increased with acne duration.

SCAR-S is a practical, validated, global system for acne scar evaluation and is clinically relevant in overall severity grading of acne.