Novel facial cosmetic area 'O zone' shows unique characteristics in sebum excretion and acne lesion distribution

Background We usually divided cosmetic facial zone into the T zone and U zone by the level of sebum secretion. Our recent studies suggested that the perioral area showed different characteristics in the aspect of acne development. Objective To investigate the unique characteristics of the O zone (perioral area) among the three facial areas. Methods A total of 102 patients clinically diagnosed as acne vulgaris were included. The acne lesions were counted from the clinical digital photographs by facial areas. The sebum level was measured using Sebumeter®. Area‐weighted (AW) sebum and AW density of three areas of face were calculated. Statistical analysis was performed according to age and gender. Results There were no differences in the mean AW sebum level between the gender and age groups. Male has higher AW density of acne lesions than female at the O zone. The mean AW density of acne lesions on the NT zone, U zone, and whole face showed decrease by age, but at the O zone, 21–30 years group showed the highest mean AW density of acne. Limitations Age‐ and gender‐matched patients do not represent the whole acne patients. Conclusion We suggested that the O zone is an independent facial zone, which showed a moderate‐to‐high sebum secreting area, maintained the acne lesions development by age, and predominated acne lesions in the male acne patients than female acne patients. Therefore, the O zone should be separated from the usual cosmetic T zone, and NT zone should replace the old T zone.