Comparison of cheek and forehead regions by bioengineering methods in women with different self-reported "cosmetic skin types"

Background/aims: Understanding structural and functional differences between facial areas is necessary for the formulation of cosmetics and dermatological preparations well tailored to the skin's biophysical characteristics. The objective of the present study was to compare biophysical parameters on malar and frontal facial areas of healthy women classified according to self-reported cosmetic skin types. Methods: The study population comprised 253 women aged from 20 to 50 years who did not display any signs of dermatological disease. Women declared spontaneously their cosmetic skin type. Skin capacitance, sebum casual level, skin temperature, transepidermal water loss (TEWL), skin colour and relief were assessed on cheeks and forehead in a controlled environment. Results: All biophysical parameters showed statistically significant differences between the two zones. Mean a* chromametric values and TEWL values were significantly higher on cheeks. In contrast, mean b* chromametric values and sebum casual levels showed the highest values on the forehead. Moreover, skin capacitance, temperature, roughness and L* chromametric value showed minor, while statistically significant, differences between the two zones. With marginal exceptions, the differences between the facial zones for each biophysical parameter remained statistically significant, irrespective of self-reported skin type. Conclusion: Biophysical parameter mean values differ between frontal and malar zones regardless of self-reported skin type. Except for the elevated sebum casual levels in "greasy" and "combined skin, no single or combined biophysical characteristics could be linked to any of the self-reported skin types. Furthermore our data confirm that in contrast to the common belief that "dry" skin is associated with reduced sebum production, sebum levels in women declaring to have "dry" skin and those declaring to have "normal" skin were not found to be different.