Integration of high-frequency ultrasound with the Global Acne Grading System for prediction of treatment efficiency in acne vulgaris

PURPOSE: This study aimed to establish a novel acne scoring system (GAGS-HFUS) that combined the Global Acne Grading System (GAGS) with high-frequency ultrasound (HFUS), and to evaluate its predictive value for unfavorable treatment response in patients who have moderate-to-severe acne. METHODS: This prospective study recruited consecutive patients with mild-to-severe acne vulgaris. The GAGS-HFUS was developed based on the HFUS-detected morphological characteristics of acne and the GAGS facial region classification. Acne severity was assessed using both ultrasonic scales (the GAGS-HFUS, Sonographic Scoring System for Acne [SSSA], and Sonographic Scoring of Acne [SOS-Acne]) and a clinical scale (the Investigator Global Assessment [IGA]). Three months of followup were conducted in a subgroup of 34 patients with moderate-to-severe acne treated with oral isotretinoin. Univariate and multivariate Poisson regression analyses were conducted to determine the predictive value of GAGS-HFUS for unfavorable treatment response in this subgroup. RESULTS: Overall, 60 patients with mild-to-severe acne (mean age, 24 years; range, 16 to 34 years; 25 males) were enrolled. The GAGS-HFUS demonstrated substantial agreement with SOS-Acne (Spearman rank correlation coefficient [Rs], 0.864; kappa, 0.713) and IGA (Rs, 0.837; kappa, 0.660). In the follow-up cohort of 34 patients with moderate-to-severe acne, GAGS-HFUS score was identified as an independent predictor of unfavorable treatment response (risk ratio, 1.125; P=0.002). Its predictive performance (area under the receiver operating characteristic curve, 0.936; P<0.001) was superior to those of IGA and SOS-Acne. CONCLUSION: GAGS-HFUS is an independent predictor of unfavorable treatment response in patients with moderate-to-severe acne, underscoring its value in the strategic management of acne.