Development and validation of a photonumeric scale for evaluation of facial skin texture

Background: A validated scale is needed for objective and reproducible comparisons of facial skin roughness before and after aesthetic treatment in practice and in clinical studies. Objective: To describe the development and validation of the 5-point photonumeric Allergan Skin Roughness Scale. Methods: The scale was developed to include an assessment guide, verbal descriptors, morphed images, and real subject images for each grade. The clinical significance of a 1-point score difference was evaluated in a review of image pairs representing varying differences in severity. Interrater and intrarater reliability was evaluated in a live-subject validation study (N = 290) completed during 2 sessions occurring 3 weeks apart. Results: A score difference of ≥1 point was shown to reflect a clinically meaningful difference (mean [95% confidence interval] absolute score difference 1.09 [0.96-1.23] for clinically different image pairs and 0.53 [0.38-0.67] for not clinically different pairs). Intrarater agreement between the 2 validation sessions was almost perfect (weighted kappa = 0.83). Interrater agreement was almost perfect during the second rating session (0.81, primary end point). Conclusion: The Allergan Skin Roughness Scale is a validated and reliable scale for physician rating of midface skin roughness.