Phototrichogram analysis of normal scalp hair characteristics with aging

Background: Phototrichogram analysis of normal scalp hair characteristics in Asian populations is not well characterized. Objective: To investigate the normal hair characteristics of South Koreans using a phototrichogram. Methods: We enrolled 674 males and 683 females between the ages of 10 and 69. Hair density, thickness and the white hair percentage were measured via phototrichogram. Six scalp sites, including front, top, the peak between top and back, back, and the right and left sides were targeted. Results: The mean hair density, hair thickness, and the white hair percentages were not significantly different between genders at any scalp site. The mean hair density and thickness were significantly different according to scalp sites. Hair density declined with age, especially at the peak between the top and back. Males and females showed different patterns of aging in hair density. Hair thickness changed little with age. Mean hair thickness generally tended to increase until the 20s, reach a plateau between the 20s and 50s, and decrease after the 50s. The mean white hair percentages were 1.84 ± 4.24% in males and 1.66 ± 4.21% in females. The mean white hair percentages were significantly increased in subjects over 40 years of age. Conclusion: We described the normal characteristics and aging patterns of scalp hair in a Korean population.