Skin pores (SP), as they are called by laymen, are common and benign features mostly located on the face (nose, cheeks, etc) that generate many aesthetic concerns or complaints. Despite the prevalence of skin pores, related literature is scarce. With the aim of describing the prevalence of skin pores and anatomic features among ethnic groups, a dermatoscopic instrument, using polarized lighting, coupled to a digital camera recorded the major features of skin pores (size, density, coverage) on the cheeks of 2,585 women in different countries and continents. A detection threshold of 250 μm, correlated to clinical scorings by experts, was input into a specific software to further allow for automatic counting of the SP density (N/cm2) and determination of their respective sizes in mm2. Integrating both criteria also led to establishing the relative part of the skin surface (as a percentage) that is actually covered by SP on cheeks. The results showed that the values of respective sizes, densities, and skin coverage: 1) were recorded in all studied subjects; 2) varied greatly with ethnicity; 3) plateaued with age in most cases; and 4) globally refected self-assessment by subjects, in particular those who self-declare having “enlarged pores” like Brazilian women. Inversely, Chinese women were clearly distinct from other ethnicities in having very low density and sizes. Analyzing the present results suggests that facial skin pore’s morphology as perceived by human eye less result from functional criteria of associated appendages such as sebaceous glands. To what extent skin pores may be viewed as additional criteria of a photo-altered skin is an issue to be further addressed.

Three recent papers 1-3 described a new Instrument-GPkSin ® (GPOWER) represented in Figure 1-that records, in vivo, both the skin hydration status and the TEWL on the same skin site (a small skin area, ≈1 cm 2) within seconds, since integrating two probes within the same body. As this instrument is connected to a smartphone application via a Bluetooth system, the provided data are immediately transferred, together with date, time of the recording and environmental Temperature (C°). Not only the skin hydration status and TEWL values given by the GPSkin ® were found highly correlated to other validated instruments 4,5-Corneometer ® (Courage and Khazaka Company ™), Tewameter ® (Courage and Khazaka Company ™), Aquaflux AF200 ® (Biox systems ™)-but they were accurate enough to significantly differentiate two formulae containing slightly different and low Glycerol contents (eg, 7% and 10% w/w). In addition, as important finding, this instrument showed that the skin hydration provided by a formula with a very high glycerol content (40%), reduced the TEWL by about 50% on the same skin site. Although of an easy handling (ergonomic, light, etc), the GPSkin ® body has nevertheless to be gently applied perpendicularly onto the skin surface, a positioning needed by the TEWL probe to fully perform. Such verticality is less a limiting factor in the recording of the skin hydration as the two impedance-measuring electrodes (located in the skin-contacting crown) are always closely connected to the skin surface. These conditions were met in two previously quoted studies 1,3