141 Focus on triggering factors in sensitive skin: two biomarkers in a new heat-cold stress in vivo model

Abstract

Sensitive skin syndrome (SSS) is characterized by barrier function alteration and inflammation in response to several stimuli (mechanical, chemical, thermal, pollution…) but no consensus exists on how to assess SSS. In this context, we developed an innovative model with heat-cold stress to evaluate in subjects with SSS the impact of a dermocosmetic product on two biomarkers, IL-1α and S100A8/9. To confirm its efficacy, the product was evaluated on skin barrier function, immediate and long-lasting soothing effect after stripping/chemical irritation (temperature, microcirculation, capsaicin test), and on Asiatic and Caucasian subjects. In an intra-individual comparative study, 30 females with SSS applied the product on one half-face for 28 days twice daily. At day 0 (D0) and D28, heat-cold stress was performed on both half-faces (radiofrequency system and dry air by 3 cycles 45±5°C,15±5°C). Before and after stress, IL-1α and S100A8/9 release, hydration and global clinical scoring of unpleasant sensations were measured. At D28, the product significantly improved skin barrier and presented a soothing effect whatever the triggering factors. In addition, up to 91% of Asiatic and Caucasian sensitive skin subjects judged the product efficient and significantly improving the burden of sensitive skin (BoSS score -14.1%). The product significantly reduced IL-1α after heat-cold stress at D0 (32.6%, p<0.001), and at D28 (27.7%, p<0.01) vs control. At D0 and D28, the S100A8/9 increase with heat-cold stress was prevented by the product. Moreover, the product significantly improved hydration (up to +45%), and the global clinical scoring (down to -50%) before and after heat-cold stress vs control. Thus, the dermocosmetic product protected skin from mechanical, chemical, and heat-cold aggressions, in addition to pollution/UV previously studied. Through this innovative model, IL-1α and S100A8/9 seems to be relevant biomarkers to assess SSS.