Quantifying dyspigmentation in facial skin ageing: an explorative study

Objective: The skin melanin system is affected by ageing, resulting in dyspigmentation with associated clinical and psychosocial consequences. In dark skinned phenotypes, broad evidence is available, whereas little is known about pigmentary changes in fair-skinned Caucasians. The objective of this study was to investigate age-related changes in facial pigmentation and dyspigmentation in subjects of skin phototypes II-III and to develop and test parameters for quantifying dyspigmentation.

Methods: Twenty-four skin healthy female subjects were recruited in three distinct age groups (30-40, 50-60, 70-80 years). Skin colour was measured by Mexameter and Chromameter. Skin dyspigmentation was measured by clinical evaluation and newly developed image-processing parameters on the cheeks and the forehead. The reliability of the clinical evaluation was investigated by intraclass correlation coefficients between three raters, and the validity of the dyspigmentation parameters was analysed by bivariate correlations with related measures.

Results: Skin lightness decreased with increasing age. Clinical dyspigmentation scores showed positive associations with chronological age ranging between 0.452 and 0.606. RBX(®) -Brown transformation-based hyperpigmentation and hypopigmentation indices increased with age, whereas the overall pigmentation intensity decreased with age at the cheeks. The image analysis-based parameters showed strong associations with the clinical scores and related measurements.

Conclusion: We demonstrated age-related changes in the facial colour and dyspigmentation of fair-skinned Caucasian females. An increase in dyspigmentation was found by clinical scoring and the RBX(®) -Brown transformation-based pigmentation indices. The validity of hyper- and hypopigmentation indices and overall pigmentation intensity was supported. The RBX(®) transformation-based pigmentation indices might be applied in future studies to complement or substitute clinical evaluation.