RESUMO
BACKGROUND: A good acne grading system should reflect epidemiological and clinical features of a particular patient group. Current Korean acne grading systems are mostly based on the skin colors, epidemiology, and clinical features of Western countries, which make them less than being ideal for Korean acne patients. OBJECTIVE: We tried to devise an acne grading system based on clinical and epidemiological characteristics of Korean acne patients. This system is intended for use in primary care setting as well as in research purposes. METHODS: In the formulation of a new acne grading system, a panel of 5 dermatologists from 5 referral centers took into account the degree of complexity of the system, criteria for severity as well as skin colors through the review of clinical photographs of 250 acne patients. The new grading system then underwent inter-rater and intra-rater discrepancy assessment and simulation with 149 patient photos to find out an optimal epidemiological representation. RESULTS: We developed 6-scale grading system with both standard pictures and ranges of number of lesions as criteria. Intra-rater and inter-rater reproducibility turned out to be moderate to strong, suggesting clear instruction and easy performance. Simulation with 4 different models yielded best parameter ranges for the optimal criteria. CONCLUSIONS: With the feedback from the large-scale field applications, this new acne grading system will serve as a multipurpose acne grading system for Korean patients.