Eur J Dermatol 2013; 23(6): 849-56

Clinical report

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Jung Eun KIM1 Joo Hyun LEE1 Kwang Hyun CHOI1 Won-Soo LEE2 Gwang Seong CHOI3 Oh Sang KWON4 Moon Bum KIM5 Chang-Hun HUH6 Chull-Wan IHM7 Young Chul KYE8 Byung In RO9 Woo-Young SIM10 Do Won KIM11 Hyung Ok KIM1 Hoon KANG1 Departments of Dermatology at 1 St. Paul’s Hospital, College of Medicine, 620-56, Jeonnong-dong, Dongdaemoon-ku, Seoul, Korea 2 Wonju College of Medicine, Wonju, Korea, 3 College of Medicine, Incheon, Korea, 4 Seoul College of Medicine, Seoul, Korea, 5 School of Medicine, Busan, Korea, 6 Seoul Bundang Hospital, Seongnam, Korea, 7 Chonbuk Medical School, Jeonju, Korea, 8 College of Medicine, Korea University, Seoul, Korea, 9 Myongji Hospital, Goyang, Korea, 10 College of Medicine, Kyunghee University, Seoul, Korea, 11 Kyungpook School of Medicine, Daegu, Korea

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. Key words: Hair characteristics, Hair density, Hair thickness, White hair, Phototrichogram, Aging

Reprints: H. Kang Article accepted on 7/16/2013

doi:10.1684/ejd.2013.2170

T

he current diagnosis and classification of patterned hair loss (PHL) relies only on the “pattern” of the general appearance of hair loss, such as the frontal hair line and the degree of baldness [1] and is quite subjective. Due to individual differences, some overlap in hair parameters exist between normal populations and patients with hair loss [2, 3]. Quantitative standards of various hair parameters are necessary in order to diagnose hair loss disorders accurately, assess response to treatment and measure the efficacy of new medicines. It is still controversial as to whether PHL is a distinct disease or simply senile change [1, 3]. Thus, it is very important to know how hair changes with aging in the normal population, so that correct diagnoses of hair loss disorders such as PHL and telogen effluvium (TE) can be made. Although some clinical researchers have focused on hair characteristics and the prevalence of PHL in

EJD, vol. 23, n◦ 6, November-December 2013

various age ranges and races [4-6], a proper definition of the characteristics of “normal hair” has not been carried out. Up until now, PT analysis of scalp hair characteristics in Asians has only been performed on a small number of subjects with a confined age range, gender distribution and on limited scalp sites [4, 7, 8]. There has been little evidence regarding how normal scalp hair changes with age according to scalp sites across populations. We aimed to investigate the normal scalp hair characteristics of Koreans at various scalp sites in various age groups and to correlate these changes with age in a large crosssectional study. To the best of our knowledge, this is the first and largest clinical observation with PT analysis at multiple representative sites on the entire scalp and which was performed in a population without hair loss, with an even age and gender distribution.

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To cite this article: Kim JE, Lee JH, Choi KH, Lee W-S, Choi GS, Kwon OS, Kim MB, Huh C-H, Ihm C-W, Kye YC, Ro BI, Sim W-Y, Kim DW, Kim HO, Kang H. Phototrichogram analysis of normal scalp hair characteristics with aging. Eur J Dermatol 2013; 23(6): 849-56 doi:10.1684/ejd.2013.2170

Copyright © 2017 John Libbey Eurotext. Téléchargé par NYU LANGONE MED CTR SCH OF MED HEALTH SCIENCES LIBRARY le 30/03/2017.

Subjects and methods This study was approved by the institutional review board of each center and all subjects gave informed consent. A total of 12 South Korean centers (St. Paul’s Hospital, Yonsei University Wonju Christian Hospital, Inha University Hospital, Seoul National University Hospital, Pusan national University Hospital, Seoul National University Bundang Hospital, Chonbuk National University Hospital, Korea University Anam Hospital, Kwandong University Myongji Hospital, Gangdong Kyunghee University Hospital, Kyungpook National University Hospital, Seoul St. Mary’s Hospital) participated in this study. The subjects were recruited from general dermatology clinics, with 120 subjects (60 male, 60 female, and 10 subjects per decade of life between 10 and 69) recruited per hospital between April 1, 2010 and May 31, 2011. A total of 1357 subjects (674 males and 683 females) without hair loss were enrolled in this study. Exclusion criteria include the following conditions: various types of hair loss disorders and scalp skin diseases, autoimmune diseases, connective tissue diseases, moderate to severe diabetes mellitus or thyroid diseases or liver disease, systemic metastatic cancer, rapid weight reduction in the prior 6 months, anemia, chronic renal failure, syphilis, current use of drugs associated with hair growth, or corticosteroids, immunomodulators, or chemotherapeutic agents, the use of products intended to increase hair growth, or permanent wave, bleaching, or hair dyeing within 1 month prior to study enrollment. We selected six scalp sites to reflect the characteristics of scalp hair as generally as possible. These sites were determined using the nearest anatomical structures of the head to standardize each center’s measurement site. (S1 (front): 2cm towards the top of the head from the midpoint of frontal hair line, S2 (top): midpoint of imaginary line connecting both external auditory meatus on the top of the scalp, S3 (between top and back): the peak between the top and back of the scalp, S4 (back): the external occipital protuberance of the back of the scalp, S5 (left side): the left temporal sites located 6 cm above the left external auditory meatus, S6 (right side): the right temporal sites located 6 cm above from the right external auditory meatus). The examination of hair characteristics was performed using a computerized hand-held dual camera USB PT system (Folliscope® , LeedM Corporation, Seoul, South Korea) and Folliscope PT® software (LeedM Corporation, program version 2.8) in every center. The measurement methods of hair diameter, thickness and white hair percentage are shown in figure 1. All values were expressed as mean ± standard deviation (SD). For analysis of intergroup comparisons, the t-test and the Mann-Whitney test, one-way analysis of variance (ANOVA) and the Dunnett-T test were conducted. A p value of < 0.05 was considered statistically significant.

Results Hair density Tables 1-2 show the mean value of hair density according to gender, scalp site and age group, respectively. The

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mean hair densities were 163.54 ± 39.40 hairs/cm2 in males and 161.50 ± 38.52 hairs/cm2 in females. The mean hair density of each site was not significantly different between genders. The top of the head and the peak between the top and back of the head had the highest mean hair density in females and males, respectively. Both sides of the head showed the lowest hair density in both genders. Statistically significant differences in mean hair density were detected between measured scalp sites, regardless of age and gender. In particular, the back of the head was significantly different when compared to all other sites (table 2). Moreover, statistically significant differences in mean hair density were detected between age groups, regardless of gender or scalp site (table 2). Patients in their second decade of life showed the highest mean hair density, after which hair density decreased (figure 2). The rate of change of hair density with age varied according to scalp site and showed different patterns of loss between males and females. The rate of decrease in hair density with age was the highest (slope = -0.60) on the top of the head, followed by the area between the top and back, and the lowest on both sides. In females, the rate of change between the top and back of the scalp showed a much faster (slope = -0.856) decrease than the front (slope = -0.46), the top (slope = -0.49), and the back (slope = -0.38). Both sides (slope = -0.06) were less affected by aging. The area between the top and back of the scalp showed the strongest relationship (r2 = -0.70) with age, regardless of gender.

Hair thickness The mean hair thickness is summarized according to age group and scalp site in table 3. The mean hair thickness was 92␮m, and was not significantly different between genders at any scalp site. The hair on both sides was thickest in most age groups, followed by the back of the head, although statistically significant differences were not detected in the mean hair thickness for multiple comparisons. Mean hair thickness was not significantly different between the six age groups in all scalp sites (table 3). However, from the mean hair thickness-age curve, we found that mean hair thickness generally tended to increase until the 20s, reach a plateau between the 20s and 50s, and decrease after the 50s regardless of scalp site or gender (figure 3). The small peaks shown in figure 3 seem to be the consequence of extremely large standard deviations.

The white hair percentages The mean white hair percentages are summarized in table 4, according to age groups and site. The mean white hair percentages were 1.84 ± 4.24% in males and 1.66 ± 4.21% in females. There were no statistically significant differences between genders at any scalp site. Within the six age groups, the mean white hair percentages did not show a significant difference according to scalp site. Hair graying increased with advancing age (figure 4). Statistically significant differences in the mean white hair percentages were detected between the 40s, 50s, 60s, and the other age groups in multiple comparisons (table 4). EJD, vol. 23, n◦ 6, November-December 2013

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A

B

Figure 1. Example of measurements using Folliscope PT® software (LeedM Corporation, program version 2.8). A 50-fold lens was used to assess hair density per cm2 and white hair percentage and a 100-fold lens was used to measure the hair thickness (␮m). The actual sizes of the analytic field of the 50-fold and 100-fold lenses were 36.48 mm2 and 9.28 mm2 , respectively. A) Hair density. Hair counting was conducted manually. B) Hair thickness. Hair thickness was measured by mouse point dragging from one end of short axis of the hair shaft to the other under 100-fold magnification. The hair shaft area selected for measurement of thickness was within 1 cm of the follicular ostium on the computer monitor. Five to ten hairs were selected randomly for thickness measurement. (A and B, Original magnifications: A ×50; B ×100.).

Discussion Hair density and thickness varied according to scalp site. The maximum hair density was in the top and the peak between the top and the back in all age groups, while hair density was the lowest in both temporal areas. Also, hair EJD, vol. 23, n◦ 6, November-December 2013

density on the top of the head was higher than that in the occipital area, consistent with the results of previous studies [9, 10]. Hair thickness was the highest in the temporal area in all age groups. Contrary to our expectation, the occipital area, which is usually spared in patients with androgenetic alopecia (AGA), did not show higher hair thickness than

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Table 1. The mean hair density (hair/cm2 ) of Koreans with normal scalp hair according to gender and scalp site Gender

Total NO. of cases

Scalp site

Mean hair density

Females

683

Males

674

S1 S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6

164.82 ± 48.33 165.20 ± 49.88 165.22 ± 50.85 151.64 ± 48.33 127.68 ± 49.91 122.69 ± 46.83 166.99 ± 50.71 166.49 ± 50.95 169.68 ± 95.24 152.49 ± 63.42 129.05 ± 46.15 126.05 ± 60.82

Data expressed as mean ± SD. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the head

other sites. Interestingly, the hair parameters of the sides of scalp did not show bilateral symmetry. Hair density peaked in the second decade of life and gradually declined with age at all scalp sites in both genders. Scalp hair showed different aging patterns according to the scalp site and gender. The top of the scalp and the peak between top and back were the sites that showed the most significant hair density decrease with aging in males and females, respectively. Both sides showed little aging change in hair density across genders. Hair thickness slightly increased during the 10s, reached a plateau between the 20s and 50s, and decreased after the 50s in all scalp sites. The white hair percentage increased after the 40s and significantly increased every 10 years, with similar patterns at multiple scalp sites. Some values in hair density and thickness showed extremely large standard deviations. We think that this error resulted from inter-individual differences or measurement errors. There were no significant differences in mean hair density or thickness between genders, which was consistent with previous results [8]. The mean hair density and thickness found in the current study were higher than the results of previous Korean studies [8], but were similar to our previous study [7]. A comparison of our results with published data regarding hair characteristics in White (Caucasian) [11], Black (central and western African, all females: normal scalp hair, 10 of the males: normal scalp hair, 9 of the males:

AGA) [12] and Japanese [4] populations is summarized in table 5 (In order to accurately compare results, we selected the 20s age group from our study). Our results showed that hair density in Koreans is significantly lower than that in White and Black populations [12, 13]. This finding is consistent with follicular counts from scalp biopsy specimens [14]. The sample size in the Caucasian population is too small and may lack the precision needed to provide reliability. However, Loussouarn et al. [12] reported previously unmentioned results of hair densities on the vertex and occipital area in a Caucasian population and the result also showed higher than our data (vertex: 243 ± 58 hairs/cm2 , occipital area: 216 ± 52 hairs/cm2 ; 45 subjects: 23 females, 22 males, mean age: 28 years, 9 of the males: AGA). Moreover, hair density in Japanese subjects [4] was very different from our study’s results, though we considered race in both countries to be similar. Hair density in Japanese females was instead more similar to that in the White population than that in Koreans. However, another study of Japanese females showed very similar hair densities to our results (67 subjects, mean age: 33.7 years, hair density: 166.2 hairs/cm2 on the upper parietal area) [15]. Hair thickness in Koreans was slightly thicker than in White [11] and Japanese [4] populations. Another study [16], using trichograms to measure hair characteristics, reported that hair thickness in White subjects was thinner than that reported by the aforementioned study [11]. These discrepancies in hair parameters may result from subject race, total number of subjects, or methodological differences. The maximum mean hair density was seen in subjects in the second decade of life and steadily declined with age. Consistent with our results, Robbins et al. [6] showed that the maximum mean hair density of Caucasian females without hair loss was seen in their 20s, which is the earliest age among available data. Tajima et al. [4] reported that hair density increases with age until the 20s and decreases thereafter in Japanese females without hair loss. They suggested that the growth and maturation of hair density occurs in females between the ages of 10 and 30. These subtle differences with our data are considered to result from subjects’ characteristics and the sample size. Our study included a relatively larger sample size and only subjects with normal scalp hair, whereas they enrolled subjects with no or less hair loss. Since we enrolled subjects with an even age distribution in the 10s in a large data set, our data is convincing to conclude that hair density gradually decreases with age after peaking in the second decade of life in a normal Korean population as well as in Asian and other

Table 2. The mean hair density (hair/cm2 ) of Koreans with normal scalp hair according to age group and scalp site Age group (years) 10-19 20-29 30-39 40-49 50-59 60-69

Scalp site S1

S2

S3

S4

S5

S6

177.00 ± 45.61 174.18 ± 82.10 166.62 ± 38.11 162.31 ± 35.37 163.71 ± 36.06 154.83 ± 36.47

176.53 ± 42.97 178.21 ± 83.47 166.68 ± 38.90 160.86 ± 36.79 161.37 ± 38.95 153.79 ± 36.90

185.39 ± 136.45 179.57 ± 89.20 168.49 ± 37.23 164.30 ± 56.71 157.32 ± 35.50 153.00 ± 34.74

162.32 ± 87.42 160.30 ± 73.21 152.91 ± 40.08 149.14 ± 36.40 146.66 ± 38.26 142.25 ± 33.43

129.95 ± 43.64 133.43 ± 56.62 128.18 ± 42.70 129.59 ± 42.48 125.95 ± 44.41 124.27 ± 40.13

127.17 ± 43.35 128.81 ± 59.86 123.22 ± 44.82 127.93 ± 78.93 120.84 ± 44.69 118.41 ± 41.38

Data expressed as mean ± SD. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the headS1 * S4-6; S2 * S4-6; S3 * S4-6; S4 * S5, 6; 10s * 30s, 40s, 50s, 60s; 20s * 30s, 40s, 50s, 60s*Statistically significant difference: p –value < 0.05

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EJD, vol. 23, n◦ 6, November-December 2013

104

190 S1 S2 S3 S4 S5 S6

170

S1 S2 S3 S4 S5 S6

102 100

Mean hair thickness (µm)

Mean hair density (hair/cm2)

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180

160 150 140 130

98 96 94 92 90 88 86

120

84 110

82 10-19

20-29

30-39

40-49

50-59

60-69

10-19

20-29

30-39

40-49

50-59

60-69

Age group

Age group

Figure 2. The mean hair density (hair/cm2 ) of Koreans with normal scalp hair according to age group and scalp site. Data expressed as mean ± SD. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the head *Because a few cases showed extremely large values of hair density, the standard deviation also had a large value.

Figure 3. The mean hair thickness (␮m) of Koreans with normal scalp hair with aging according to scalp site. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the head.

of females, males and females showed similar hair thickness patterns with age in our study, which supports the conclusion that chronological aging [19] is more strongly related to hair thinning than menopausal status. We previously reported a PT analysis of the patterns of female pattern hair loss (FPHL) according to the Ludwig classification and TE and compared them with normal Korean controls [7]. Since the current data is consistent with our previously published data of normal controls, we compared those hair parameters of FPHL patients [7] with the age-matched normal population of the current study (20s40s) (figure 5). Whereas the hair density of normal controls peaked on the top of the head and was the lowest on the sides, the top of the heads of patients with FPHL and TE showed the lowest density or had a similar hair density to the sides. In terms of hair thickness, patients with FPHL and TE showed the thinnest hair on the top of the head. The mean hair density on the front and the top of the scalp of patients with FPHL Ludwig I group was 90% and 88% of those of the normal population, respectively. In the FPHL Ludwig II group, the mean hair density of the front and top sites was 87% and 80% of a normal population and the densities of the Ludwig III group were 80% and 70%, respectively. On the front and top sites, the mean hair thickness of patients with FPHL ranged from 71 to 84% of that of a normal population. From these findings, we suggest

races. The reduction of hair density with aging has been explained as being due to a shortened duration of the anagen period and delayed re-entry into anagen after hair shedding [17]. These changes were most prominent between the top and back of the scalp and occurred faster in females than in males. This difference might be due to hormonal effects related to pregnancy, childbirth and the menopause [18]. We calculated the rate of yearly decrease in hair density over all scalp sites. This information regarding the normal aging pattern of scalp hair can be applied to anticipate an individualized, future image of general hair appearance, which could provide guidance to both patients and physicians when choosing therapeutic options for hair loss diseases or anti-aging procedures. Mean hair thickness showed minimal variation with aging. Birch et al. [5] and Tajima et al. [4] reported that hair thickness increases until the 40s and starts to decline from 40 years of age in Caucasian and Japanese females without hair loss, respectively. Menopause has been suggested as a contributing factor in decreased hair density and hair thinning in middle-aged women [18], but this is still controversial. Although we did not investigate menopausal status

Table 3. The mean hair thickness (␮m) of Koreans with normal scalp hair according to age group and scalp site Age group (years) 10-19 20-29 30-39 40-49 50-59 60-69

Scalp site S1

S2

S3

S4

S5

S6

89 ± 30 88 ± 26 94 ± 29 93 ± 65 86 ± 25 86 ± 26

91 ± 49 88 ± 25 91 ± 28 91 ± 47 93 ± 70 85 ± 26

90 ± 29 90 ± 27 92 ± 30 88 ± 26 88 ± 27 85 ± 26

91 ± 31 90 ± 26 100 ± 83 93 ± 54 94 ± 56 94 ± 67

98 ± 59 90 ± 27 102 ± 84 95 ± 57 91 ± 26 92 ± 63

103 ± 82 92 ± 26 95 ± 30 93 ± 46 89 ± 26 89 ± 25

Data expressed as mean ± SD. The front (S1), top (S2), peak between the top and back (S3), back(S4), left side(S5), right side(S6) of the head. EJD, vol. 23, n◦ 6, November-December 2013

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Table 4. The mean white hair percentage (white hair number x 100/total hair number) of Koreans with normal scalp hair according to age group and scalp site Age group (years)

Scalp site S2

S3

S4

S5

S6

0.11 ± 0.47 0.08 ± 0.35 0.21 ± 0.74 1.05 ± 2.51 3.26 ± 5.50 7.38 ± 8.02

0.12 ± 0.41 0.06 ± 0.29 0.24 ± 0.96 1.12 ± 2.58 3.17 ± 5.07 6.31 ± 7.47

0.10 ± 0.40 0.08 ± 0.31 0.16 ± 0.61 0.98 ± 2.26 2.60 ± 4.54 6.34 ± 8.60

0.14 ± 0.60 0.12 ± 0.42 0.19 ± 0.70 0.71 ± 2.02 1.95 ± 3.76 5.64 ± 8.09

0.21 ± 0.75 0.16 ± 0.57 0.24 ± 0.73 1.32 ± 3.06 3.26 ± 5.80 7.32 ± 9.09

0.14 ± 0.66 0.08 ± 0.29 0.19 ± 0.65 1.29 ± 2.89 3.77 ± 6.15 7.77 ± 9.18

Data expressed as mean ± SD. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the head10s*40s, 50s, 60s; 20s*40s, 50s, 60s; 30s*40s, 50s, 60s*Statistically significant difference: p –value < 0.05

8

Mean white hair percent (%)

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10-19 20-29 30-39 40-49 50-59 60-69

S1

S1 S2 S3 S4 S5 S6

6

4

2

0 10-19

20-29

30-39

40-49

50-59

60-69

Age group

Figure 4. The mean white hair percentages (white hair number ×100/total hair number) of Koreans with normal scalp hair according to age group and scalp site. Data expressed as mean ± standard deviation. The front (S1), top (S2), peak between the top and back (S3), back (S4), left side (S5), right side (S6) of the head.

that, on the front and top, there should be at least a 10% to 15% decrease in mean hair density and thickness when compared to an age-matched normal population in order to diagnose FPHL in Korean populations. Considering that the occipital scalp region of patients with PHL is preserved, we compared the ratio of other sites to the occiput from our results in terms of mean hair density and thickness to those of FPHL and TE patients (table 6) [7]. Differences were detected in the ratio of other sites to the occiput between the normal population and FPHL patients but were not detected between TE patients and

the normal population. While the S1/S4 and S2/S4 ratios of hair density were larger than 1.0 in normal population, those of FPHL patients tended to show a ratio smaller than 1.0 and to gradually decrease as the Ludwig stage rose. In terms of hair thickness, the front, top, and side to back ratio was inversely correlated with the severity of FPHL. Hair thinning of both sides progressed at a similar rate as the front and top of the scalp in FPHL as the Ludwig stage rose. Since hair characteristics are different for each individual, comparison of frontal or vertex parameters with occipital hair parameters within each individual may be meaningful. The S1/S4 and S2/S4 ratios of hair density and thickness could be a reference to diagnose and assess PHL. Hair graying manifests significantly over 40 years and significantly increases every 10 years. Consistent with our results, Jo et al. [20] reported that the average onset of hair graying in Koreans was 41.6 ± 13.1 years. However, they reported that the white hair percentage of subjects beyond their 50s was about 20-40% [20], which is much higher than our results. They introduced a photographic scale to assess the percentage of white hair. In our opinion, the photographic scale should have been confirmed by PT analysis to avoid optical illumination. Inversely, small errors in PT analysis of limited areas might lead to large errors when applying those results to an entire scalp. Our study is the first trial to assess gray hair with PT analysis, and the dichotomy of the white hair percentage should be confirmed through further study. Keogh et al. _ENREF_18[21] suggested that 50% of Australians in their 50s have 50% grey hair. It is difficult to discern white hairs in populations with fair or medium hair colors. In addition, the rate of hair graying calculated from their data relied on subjective assessment. Van Neste et al. [22] proposed the simple method to differentiate between pigmented hair and non-pigmented hair in Caucasians using a alternatively

Table 5. Comparison of hair parameters between Korean, White, Black and Japanese populations Korean

Total No. of cases A range of ages (years) Mean hair density (hair/cm2 ) Mean hair thickness(␮m)

Male

Female

Male

White Female

Male

Black Female

Japanese Female

115 20-29 176.84 90

122 20-29 179.5 89

8 18-30 260 84

20 18-30 300 84

19 18-59 205 -

19 18-59 202 -

21 20-29 287.1 81

Black (central and western African, all of females: normal scalp hair, 10 of the males: normal scalp hair, 9 of the males: AGA)

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EJD, vol. 23, n◦ 6, November-December 2013

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Mean hair thickness (µm)

2

Mean hair density (hair/cm )

250

200

150

100

50

140 120 100 80 60 40 20

0

0 S1

S2

S4

S1

Scalp site FPHL: L1

S2

S4

Scalp site FPHL: L2

FPHL: L3

TE

Female control

Figure 5. Comparisons of the patterns of FPHL, TE and population without hair loss in Korean A) Hair density. B) Hair thickness.

Table 6. The ratio of other sites to the occiput for hair density and hair thickness

Normal FPHL Ludwig I Ludwig II Ludwig III

S1/S4

Hair density S2/S4

S3/S4

S5-6/S4

S1/S4

Hair thickness S2/S4

S3/S4

S5-6/S4

1.084

1.091

1.102

0.835

0.958

0.954

0.968

1.002

1.004 0.992 0.954

0.985 0.916 0.847

-

0.942 0.924 0.9

0.952 0.946 0.926

0.909 0.845 0.707

-

0.961 0.899 0.775

The front (S1), top (S2), peak between the top and back (S3), back (S4) of the head

blackish and whitish-colored reference card. White hair percentage on the top and occipital area in 12 postmenopausal females ranged from 0-85% (mean: 28.4) and 0-63% (mean: 22.8), respectively in their study [22]. There should be a difference in the white hair percentage between races. We reported the normal characteristics and aging patterns of scalp hair in Koreans at various scalp sites. We also suggest the normal range of PT data and hair parameter ratios that may aid in diagnosing PHL.  Disclosure. Financial support: Hair Research Grant of the Korean Dermatological Association. Conflict of interest: none.

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15. Ueki R, Tsuboi R, Inaba Y, Ogawa H. Phototrichogram analysis of Japanese female subjects with chronic diffuse hair loss. J Investig Dermatol Symp Proc 2003; 8: 116-20. 16. Rushton DH, de Brouwer B, de Coster W, van Neste DJ. Comparative evaluation of scalp hair by phototrichogram and unit area trichogram analysis within the same subjects. Acta Derm Venereol 1993; 73: 150-3. 17. Messenger AG. Hair through the female life cycle. Br J Dermatol 2011; 165 (Suppl 3): 2-6. 18. Mirmirani P. Hormonal changes in menopause: do they contribute to a ’midlife hair crisis’ in women? Br J Dermatol 2011; 165 (Suppl 3): 7-11.

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EJD, vol. 23, n◦ 6, November-December 2013

Phototrichogram analysis of normal scalp hair characteristics with aging.

Phototrichogram analysis of normal scalp hair characteristics in Asian populations is not well characterized...
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