title: Sebum output as a factor contributing to the size of facial pores.
abstract: BACKGROUND
  Many endogenous and exogenous factors are known to cause enlarged pilosebaceous pores. Such factors include sex, genetic predisposition, ageing, chronic ultraviolet light exposure, comedogenic xenobiotics, acne and seborrhoea. This study was an attempt to determine the factors related to enlarged pores.
  
  
  OBJECTIVE
  To assess the relationship of sebum output, age, sex, hormonal factors and severity of acne with pore size.
  
  
  METHODS
  A prospective, randomized, controlled study was designed. A total of 60 volunteers, 30 males and 30 females, were recruited for this study. Magnified images of pores were taken using a dermoscopic video camera and measured using an image analysis program. The sebum output level was measured with a Sebumeter.
  
  
  RESULTS
  Using multiple linear regression analysis, increased pore size was significantly associated with increased sebum output level, sex and age. Among the variables, sebum output level correlated most with the pore size followed by male sex. In comparing male and female participants, males had higher correlation between the sebum output level and the pore size (male: r = 0.47, female: r = 0.38). Thus, additional factors seem to influence pore size in females. Pore size was significantly increased during the ovulation phase (P = 0.008), but severity of acne was not significantly associated with the pore size.
  
  
  CONCLUSIONS
  Enlarged pore sizes are associated with increased sebum output level, age and male sex. In female patients, additional hormonal factors, such as those of the menstrual cycle, affect the pore size.
authors.affiliation: Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu, 120-752, Seoul, Korea.
authors.forename: M
authors.initials: M
authors.lastname: Roh
authors.forename: M
authors.initials: M
authors.lastname: Han
authors.forename: D
authors.initials: D
authors.lastname: Kim
authors.forename: K
authors.initials: K
authors.lastname: Chung
mesh_terms: D000152:Acne Vulgaris / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000375:Aging / Q000378:metabolism / Q000473:pathology; D046169:Dermoscopy; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology; D016062:Porosity; D011446:Prospective Studies; D012629:Sebum / Q000378:metabolism*; D012720:Severity of Illness Index; D012727:Sex Characteristics; D012867:Skin / Q000033:anatomy & histology* / Q000378:metabolism