RESUMEN
BACKGROUND: Despite the focus on facial photoaging ratings, there are few classifications developed for forearm skin aging assessment. OBJECTIVE: To develop and validate a clinical scale for the evaluation of forearm skin aging. METHODS: Three clinical dermatology faculty members selected, discussed, and appraised the main signs of forearm photoaging. The validation of the resulting scale was performed by 5 assessors who were previously trained to classify 102 photographs of forearms with different degrees of aging. Retests were performed in 15 days. RESULTS: There was significant correlation between the selected variables and the subjective global aging scale. The developed scale showed high internal consistency (Cronbach's α=0.87) and high correlation with the global photoaging scale (rho=0.92). Inter- and intraobserver final scores showed high agreement. CONCLUSION: A validated clinical photoaging scale for forearms with internal consistency, reliability, and validity was developed.