Facial skin pores: a multiethnic study

Abstract

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/cm(2)) and determination of their respective sizes in mm(2). 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.

Keywords: aging; clinical evaluation; ethnicity; imperfections; oily skin.

Figure 1

Dermascore^® device. Notes: (A) Dermascore^® device; (B) application onto the cheek; (C) and resulting standardized photographs from different prevalence of skin pores.

Figure 2

Impact of various input thresholds upon automatic detection of facial skin pores. Notes: From left to right, high to low thresholds: (A) 500 μm threshold; (B) 250 μm threshold; (C) 100 μm threshold.

Figure 3

example of correlation obtained between clinical scorings and skin pore surface in 200 Chinese women, using a 250 μm threshold of detection.

Figure 4

Changes in densities of skin pores with age and ethnic group. Notes: all 2,585 subjects were included. Data expressed as mean values ±95% confidence intervals in each age class among ethnic groups.

Figure 5

Changes in sizes of skin pores with age and ethnic group. Notes: All 2,585 subject were included. Data expressed as mean values ±95% confidence intervals in each age class among ethnic groups.

Figure 6

Changes in the relative skin surface covered by skin pores (as a percentage of total skin) with age and ethnicity. Notes: All 2,585 subject included. Data expressed as mean values ±95% confidence intervals in each age class among ethnic groups.