Emollients and the response of facial skin to a cold environment

Background It is debated whether the use of emollients, in cold weather, constitutes a protective factor or a risk factor for frostbite. Objectives To compare the effects of two emollients [oil in water (O/W) and petrolatum] on facial skin in response to cold exposure. Methods Fifteen volunteers participated in the experiment, consisting of 60 min in a cold room (-5 degreesC), preceded and followed by 30 min of acclimatization at room temperature. In the cold room, O/W was applied on one cheek and petrolatum on the other. The cheeks were exposed to wind, produced by a fan, to cool further the skin by the wind chill index. Skin temperature, redness, and transepidermal water loss (TEWL) were measured on both cheeks. Results Facial skin treated with O/W was significantly colder (up to 1.3 degreesC) than facial skin treated with petrolatum, but the difference disappeared within 20 min. Agreement between temperature measurements and subjective thermal sensations was poor (Cohen's kappa = -0.13). At no point did the paired skin redness and the paired TEWL values vary significantly. The TEWL levels were significantly lower 30 min after the cold exposure than before, but had reached pre-exposure levels the following day. Conclusions This study demonstrates that for a duration exposure of 20 min, facial skin treated with O/W achieves a lower temperature than facial skin treated with petrolatum. The two emollients had in all other aspects the same effect on the response of facial skin to cold.