Clinical Parameters Involved in Skin Tone Perception of Asian Population

Skin tone contributes critically to facial attractiveness; skin aging yellowness has become a predominant aging and skin tone concern in the Asian population. However, the clinical parameters underlying the visual perception of skin yellowness remain elusive. This study explored the relevant clinical parameters and exposome factors influencing the perception of skin yellowness.

Perceived facial skin yellowness was evaluated through three observation and rating tests involving 170 female participants. Standardized lighting and screen settings ensured consistent evaluations of randomized full face and skin-tone-adjusted images. The correlation of yellowness observation and clinical parameters was identified, helping to decode the parameters that determine perception.

The pair test showed that not only b* but also L* and skin diffused reflection determined yellowness perception commonly across age. Rating test on artificial face images confirmed the importance of both b* and L*. A preliminary model on colorimetric parameters was derived: Perceived Yellowness = 0.42b* - 0.2L* + 9.01. Further pair test demonstrated that perceived skin yellowness varied seasonally, suggesting an influence of sun exposure.

This study reveals the correlation of skin yellowness perception and clinical parameters, especially the contribution of relevant colorimetric parameters. From a third-person perspective, b*, L* and diffused reflection are key determinants of perceived skin yellowness. The observed seasonal variation in yellowness perception indicated a perceivable "seasonal skin yellowing." The findings provided new insights for developing treatments for skin aging yellowness, photoprotection and modulation of colorimetric parameters (L* and b*) and optical parameter (reflection) are highlighted as important clinical targets.