Acute effects of temperature fluctuations on skin health: A randomized, crossover trial

The skin, as the primary barrier against environmental stressors, is constantly exposed to temperature fluctuations, yet the immediate effects of acute temperature changes on molecular and lipidomic alterations remain insufficiently explored. This randomized crossover trial study was conducted with 30 healthy adults exposed to 22 °C and 32 °C for 2 h in random order. Skin sensations, facial skin visual condition, sebum levels, and protein concentrations were measured, along with lipidomic analysis and assessment of five biomarkers, including total protein, interleukin-1α (IL-1α), interleukin-1 receptor antagonist (IL-1Rα), total antioxidant capacity, and kallikrein 5. At 32 °C, participants reported their skin as oilier, stickier, and less refreshed, while at 22 °C, it was drier and tighter. Skin luminosity increased by 37.6 % (95 % CI: 1.8 %, 73.4 %) at 32 °C compared to 22 °C. Sebum secretion significantly increased at 32 °C at both 60 min [19.0 μg/cm² (95 % CI: 2.9, 35.2)] and 120 min [19.1 μg/cm² (95 % CI: 1.9, 36.3)]. IL-1α and IL-1Rα were significantly upregulated at 32 °C. Protein levels were significantly higher at 22 °C. Lipidomic analysis revealed significant alterations in triacylglycerols, especially short-chain and low unsaturated forms. These results underscore the considerable impact of acute temperature fluctuations on skin properties, with higher temperatures increasing sebum production and inflammation, while lower temperatures reduce barrier function.