Abstract
BACKGROUND: The concept of "skin quality" (SQ) has gained widespread attention, with a recent international consensus defining it and outlining four "emergent perceptual categories" (EPCs), each accompanied by specific parameters and associated measurement methods. No research has confirmed whether the parameters linked to these EPCs vary objectively with age. This gap in data is significant, as understanding how these parameters correlate with age could be essential for creating an objective, age-adjusted classification of SQ. AIM: The aim of this study was to investigate the EPC skin firmness in female facial and non-facial skin in relation to age using biophysical measurements. Reference ranges for objective assessment were determined. PATIENTS/METHODS: Three hundred healthy women (20-69 years) were divided into five age groups. The correlation between age and skin firmness measured by Cutometer and Corneometer (Courage+Khazaka electronic GmbH, Cologne, Germany) devices was evaluated across five anatomical sites: forehead, cheek, neck, décolleté, and the hand. Percentiles were used to generate reference ranges. RESULTS: Statistical analysis discloses that R2 (U(a)/U(f)), R5 (U(r)/U(e)), and R7 (U(r)/U(f)) correlated with age for all five sites and are preferably assigned to the EPC skin firmness, whereby R2 and R7 showed the strongest correlation. For the neck, significant age-related changes were found in most of the Cutometer parameters. The stratum corneum (SC) hydration showed only low correlations with age. CONCLUSIONS: R2, R5, and R7 are reliable indicators of age-related changes in skin firmness, with established reference ranges that can aid in treatment decisions and SQ assessments.