Phototrichogram Analysis of Normal Scalp Hair Characteristics with Aging

The study, which included 674 males and 683 females aged between 10 and 69 years from a South Korean population, used phototrichogram analysis to examine the characteristics of normal scalp hair across different age groups. It found that hair density decreased with age, especially at the top of the scalp for males and between the top and back for females, while hair thickness generally increased until the 20s, plateaued until the 50s, and then decreased after the 50s. The percentage of white hair significantly increased in individuals over 40 years old. No gender differences were observed in mean hair density or thickness. The study also provided PT data and hair parameter ratios that could assist in diagnosing pattern hair loss. The research was funded by the Korean Dermatological Association and reported no conflicts of interest.