10.5826/dpc.1401a96
Introduction: Peripilar sign (PPS) is a trichoscopic sign that was first described in androgenetic alopecia (AGA) and is thought to reflect the presence of perifollicular infiltrate (PFI) in histopathology.
Objectives: To study PPS in a cohort of patients with AGA and to assess its validity as a sign indicative of PFI.
Methods: One hundred patients with AGA (confirmed by trichoscopic examination) were recruited in this cross-sectional study. From those patients, frontal scalp biopsy was done for two subgroups, 22 patients with PPS and 23 patients without PPS. Both groups were compared as regards the presence of PFI.
Results: Peripilar sign was present in 50% of the 100 studied cases. No significant difference existed between those with and those without PPS as regards PFI. Peripilar sign was significantly more encountered in patients with skin type III (p=0.001). Its absence was significantly associated with lower interpretability of yellow dots (p&lt;0.001) and their scores were significantly positively correlated (r=0.498, p&lt;0.001). Peripilar sign was significantly associated with absent melanophages histopathologically (p=0.011).
Conclusion: Peripilar sign as a trichoscopic sign in AGA does not reflect PFI. It represents a dark color more encountered in patients with lighter skin types. This can be explained by the increased contrast between the dark PPS and the lighter surrounding skin in lighter skin types. Further studies using melanocyte markers and Masson Fontana's stain are needed to further verify the cause of this peri-follicular dark color. 
text/xml
2160-9381
2966
en
Iman Sany
https://creativecommons.org/licenses/by-nc/4.0
Dermatology Practical & Conceptual
perifollicular infiltrate
Peripilar Sign in Androgenetic Alopecia: Does It Really Indicate Peripilar Infiltrate?
Text.Serial.Journal
https://dpcj.org/index.php/dpc
Original Article
2024-01-31
2022-11-11
2024-01-31
2024-02-21
e2024096
Dermatol Pract Concept
Introduction: Peripilar sign (PPS) is a trichoscopic sign that was first described in androgenetic alopecia (AGA) and is thought to reflect the presence of perifollicular infiltrate (PFI) in histopathology.
Objectives: To study PPS in a cohort of patients with AGA and to assess its validity as a sign indicative of PFI.
Methods: One hundred patients with AGA (confirmed by trichoscopic examination) were recruited in this cross-sectional study. From those patients, frontal scalp biopsy was done for two subgroups, 22 patients with PPS and 23 patients without PPS. Both groups were compared as regards the presence of PFI.
Results: Peripilar sign was present in 50% of the 100 studied cases. No significant difference existed between those with and those without PPS as regards PFI. Peripilar sign was significantly more encountered in patients with skin type III (p=0.001). Its absence was significantly associated with lower interpretability of yellow dots (p&lt;0.001) and their scores were significantly positively correlated (r=0.498, p&lt;0.001). Peripilar sign was significantly associated with absent melanophages histopathologically (p=0.011).
Conclusion: Peripilar sign as a trichoscopic sign in AGA does not reflect PFI. It represents a dark color more encountered in patients with lighter skin types. This can be explained by the increased contrast between the dark PPS and the lighter surrounding skin in lighter skin types. Further studies using melanocyte markers and Masson Fontana's stain are needed to further verify the cause of this peri-follicular dark color. 
Iman Sany
2024/01/31
10.5826/dpc.1401a96
e2024096
Dermatology Department, Faculty of Medicine, Cairo University, Egypt 
2160-9381
perifollicular infiltrate
en
e2024096
Staricco RG, Miller-Milinska A. Activation of the Amelanotic Melanocytes in the Outer Root Sheath of the Hair Follicle Following Ultra Violet Rays Exposure. J Invest Dermatol. 1962;39(3):163-164.
Peripilar Sign in Androgenetic Alopecia: Does It Really Indicate Peripilar Infiltrate?
https://dpcj.org/index.php/dpc/article/download/2966/2561
              Peripilar Sign in Androgenetic Alopecia:
             Does It Really Indicate Peripilar Infiltrate?
                 Dina Abdalla1, Manal Bosseila1, Mona R.E. Abdel-Halim1, Iman Sany1


1 Dermatology Department, Faculty of Medicine, Cairo University, Egypt



Key words: androgenetic alopecia, trichoscopy, histopathology, peripilar sign, perifollicular infiltrate
Citation: Abdalla D, Bosseila M, R.E. Abdel-Halim M, Sany I. Peripilar Sign in Androgenetic Alopecia: Does It Really Indicate Peripilar
Infiltrate? Dermatol Pract Concept. 2024;14(1):e2024096. DOI: https://doi.org/10.5826/dpc.1401a96
Accepted: May 15, 2023; Published: January 2024
Copyright: ©2024 Abdalla et al. This is an open-access article distributed under the terms of the Creative Commons Attribution-
NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use,
distribution, and reproduction in any medium, provided the original authors and source are credited.
Funding: None.
Competing Interests: None.
Authorship: All authors have contributed significantly to this publication.
Corresponding Author: Dina Abdalla Abdalla Mohamed, MSc, 1 Land of Intelligence, October Gardens, Cairo, Egypt.
E-mail: dina.a.mohamed@residents.kasralainy.edu.eg




  ABSTRACT              Introduction: Peripilar sign (PPS) is a trichoscopic sign that was first described in androgenetic
                        ­alopecia (AGA) and is thought to reflect the presence of perifollicular infiltrate (PFI) in histopathology.
                        Objectives: To study PPS in a cohort of patients with AGA and to assess its validity as a sign indicative
                        of PFI.
                        Methods: One hundred patients with AGA (confirmed by trichoscopic examination) were recruited
                        in this cross-sectional study. From those patients, frontal scalp biopsy was done for two subgroups,
                        22 patients with PPS and 23 patients without PPS. Both groups were compared as regards the presence
                        of PFI.
                        Results: Peripilar sign was present in 50% of the 100 studied cases. No significant difference exist-
                        ed between those with and those without PPS as regards PFI. Peripilar sign was significantly more
                        encountered in patients with skin type III (p=0.001). Its absence was significantly associated with
                        lower interpretability of yellow dots (p<0.001) and their scores were significantly positively correlated
                        (r=0.498, p<0.001). Peripilar sign was significantly associated with absent melanophages histopatho-
                        logically (p=0.011).
                        Conclusion: Peripilar sign as a trichoscopic sign in AGA does not reflect PFI. It represents a dark
                        color more encountered in patients with lighter skin types. This can be explained by the increased
                        contrast between the dark PPS and the lighter surrounding skin in lighter skin types. Further studies
                        using melanocyte markers and Masson Fontana's stain are needed to further verify the cause of this
                        peri-follicular dark color.




Original Article | Dermatol Pract Concept. 2024;14(1):e2024096                                                                            1
Introduction                                                         were patients with patchy hair loss, diffuse alopecia areata,
                                                                     cicatricial alopecia, associated inflammatory scalp disorders
Androgenetic alopecia (AGA) is a very common type of hair            or collagen vascular disorders, as well as AGA patients using
loss. It is characterized by progressive miniaturization of hair     scalp topical steroids in the previous 2 weeks or systemic
follicles with shortening of the anagen phase, ­leading to grad-     steroids in the previous month.
ual conversion of terminal hairs into vellus hairs [1]. D
                                                        ­ iagnosis      All hundred patients were subjected to detailed history
is usually based on clinical examination, and trichoscopy is         taking including: occupation, special habits of medical impor-
usually enough to confirm the diagnosis [2]. Only rarely, a          tance, duration of hair loss, presence of trichodynia, applica-
biopsy may be required [3].                                          tion of topical minoxidil or topical steroids, hair dying, routine
    The main trichoscopic findings of AGA are: hair shaft            use of oils and creams, hair heating or straightening proce-
diameter diversity more than 20% with an increased number            dures, habitual head covering and UVR exposure. Disease
of miniaturized vellus hairs, especially in the frontoparietal       severity was clinically assessed according to Hamilton and
region, the predominance of single hair pilosebaceous units,         Norwood classification[9] or male pattern AGA and accord-
the brown and white peripilar signs (PPSs), and the yellow           ing to Sinclair Hair Density Scale for female pattern AGA [10].
dots [4].                                                               Trichoscopic features analyzed at 20 x magnification of
    The typical histopathological findings of AGA are a to-          images were:
tal number of follicles within the normal range, a decrease
in the ratio of terminal to vellus hair, and noticeable varia-       • Peripilar (PPS) sign: The color of PPS was graded as fol-
tion of shaft diameter. A mild peri-infundibular lymphocytic           lows: - = absent; += yellow, ++= light brown; +++=brown.
infiltrate and perifollicular fibroplasia are present in some        • Pigment pattern: The honeycomb pattern was graded
cases [5].                                                             as follows: - =absent, += scattered in light brown color;
    The PPS which is defined as the presence of a brown                ++=more condensed with brown color.
halo, roughly 1 mm in diameter, at the follicular ostium was         • Yellow dots: The color of the yellow dots was graded as
first described by Deloche et al. in 2004 [6] in 90% of males          follows: - = absent, += yellow, ++= light brown.
and 86% of females with AGA. The authors reported that               • Pinpoint white dots; evaluated as present or absent.
PPS significantly correlated with the perifollicular infiltrate      • White patches (localized areas of shiny fibrosis); evaluated
(PFI) seen in the papillary dermis around the infundibulum             as present or absent.
and/or the sebaceous glands. However, they did not compare           • Focal atrichia (absence of follicular openings); evaluated
those with and those without PPS as regards the presence of            as present or absent.
PFI. They suggested that both PPS and PFI are early signs of
AGA [6].                                                                A 4-mm punch skin biopsy was carried out for 45 pa-
    Since the initial explanation of PPS as a sign of PFI in         tients (who consented for biopsy taking), 22 (subgroup A)
AGA, no further studies were performed to validate this find-        with PPS in the frontal region and 23 (subgroup B) without
ing. Accordingly, the aim of the current study was to study          PPS in the frontal region. The biopsy site was standardized in
PPS in a cohort of Egyptian patients with AGA and to assess          both groups (from the frontal area, 4 cm posterior to the an-
its validity as a sign indicative of PFI by comparing AGA            terior hairline and 1 cm lateral to scalp midline). In subgroup
cases with and without PPS as regards the presence of PFI.           A, the biopsy was obtained from an area showing PPS. Biop-
                                                                     sies were routinely fixed and processed then embedded for
Methods                                                              transverse sectioning [11]. Sectioning through the isthmus
                                                                     and infundibulum up to the surface epidermis was ensured.
Patients                                                             Points assessed in every biopsy were:
This cross-sectional study conformed to the ethical stan-
dards of Helsinki Declaration and was approved by the                • Assessment of perifollicular infiltrates (PFI): The presence
­Department's Ethical Committee. An informed consent was               of PFI was evaluated in every case. For cases with PFI,
signed by the patients for participation in the study, photog-         the part of the follicular unit involved was documented.
raphy, and biopsy.                                                     The density of PFI was scored as mild, moderate, or severe
    One hundred patients (of either gender) with any grade or          according to a visual analog scale (Figure 1).
duration of AGA who are above the age of 16 years with any           • Assessment of perifollicular fibrosis (PFF): the presence
Fitzpatrick's skin type were recruited from the Outpatient             of PFF was evaluated in every case. For cases with PFF,
Clinic of the Dermatology Department, Cairo U
                                            ­ niversity.               the part of the follicular unit affected by PFF was docu-
The diagnosis of AGA was established based on classic clin-            mented. The PFF was scored as mild, moderate, or severe
ical and trichoscopic criteria [7,8]. Excluded from the study          according to a visual analog scale (Figure 2).



2                                                                        Original Article | Dermatol Pract Concept. 2024;14(1):e2024096
                Figure 1. Visual analog scale for scoring perifollicular infiltrate (PFI). a: Mild PFI, b: Moderate PFI (H&E,
                original magnification X40).




                                Figure 2. Visual analog scale for scoring perifollicular fibrosis (PFF). a: Mild PFF,
                                b: Moderate PFF with broader zone of concentric fibroplasia (H&E, original mag-
                                nification X40).



• Assessment of perivascular infiltrate: the presence of peri-          P-values less than 0.05 were considered as statistically
  vascular infiltrate was evaluated in every case, as well as           significant.
  its localization in the dermis. It was scored as mild, moder-
  ate, or severe according to a visual analog scale (Figure 3).
                                                                        Results
• Presence of melanophages.
                                                                        The studied cohort included 87 (87%) females and 13 (13%)
    Data were coded and entered using the statistical pack-             males. Their ages ranged from 16 to 67 years with a mean
age for the Social Sciences (SPSS) version 26 (IBM Corp.,               ±SD of 34±11.55 years and the duration of hair loss ranged
Armonk, NY, USA). Data was summarized using mean,                       from 0.16 to 20 years with a mean ±SD of 5.07±4.73 years.
standard deviation, median, minimum, and maximum in                     Table 1 summarizes other important demographic and clin-
quantitative data and using frequency (count) and rela-                 ical data.
tive frequency (percentage) for categorical data. Compar-                   Trichoscopic findings are illustrated in table 2. Peripilar
isons between quantitative variables were done using the                sign was detected both in the frontal and occipital areas in
non-parametric Mann-Whitney test [12]. For comparing                    50 (50%) of cases and in the occipital area only in 7 (7%)
categorical data, Chi square (χ²) test was performed. Fisher’s          of cases (Figure 4).
exact (F) test was used instead when the expected frequency                 Perifollicular infiltrate was present in 37 out of 45 biop-
is less than 5 [13]. Correlations between quantitative vari-            sies (82.2%), being mild in density in the majority of them
ables were done using Spearman correlation coefficient [14].            (89.2%). It surrounded the infundibulum in 100% of cases.



Original Article | Dermatol Pract Concept. 2024;14(1):e2024096                                                                       3
              Figure 3. Visual analog scale for scoring perivascular infiltrate. a: Mild perivascular infiltrate, b: Moderate
              perivascular infiltrate (H&E, original magnification X40).




          Table 1. Important Demographic and Clinical Data of the Studied Cohort (N=100).
                                                                                                                      Number (%)
Occupation                                                                       Indoor worker                          97 (97%)
                                                                                 Outdoor worker                            3 (3%)
Special habits of medical importance                                             Smoker                                 10 (10%)
                                                                                 Non-smoker                             90 (90%)
Trichodynia                                                                                                             34 (34%)
Application of topical minoxidil                                                                                        24 (24%)
Application of topical steroids                                                                                            3 (3%)
Use of hair dyes                                                                                                        15 (15%)
Use of hair straightening procedures                                                                                       3 (3%)
Use of hair oils/creams                                                                                                 88 (88%)
Use of hot hair styling devices                                                                                            8 (8%)
Head covering                                                                                                           85 (85%)
Exposure to ultraviolet radiation                                                Excessive                                 3 (3%)
                                                                                 Routine                                97 (97%)
Fitzpatrick skin type                                                            III                                    38 (38%)
                                                                                 IV                                     62 (62%)
Grade of hair loss      Females                                                  2                                    34 (39.1%)
                        (Sinclair Hair Density Scale)                            3                                    36 (41.4%)
                                                                                 4                                    16 (18.4%)
                                                                                 5                                       1 (1.1%)
                                                                                 Total                                 87 (100%)
                        Males (Hamilton and Norwood Classification)              1                                       1 (7.7%)
                                                                                 2                                      2 (15.4%)
                                                                                 3                                      3 (23.1%)
                                                                                 3 vertex                               3 (23.1%)
                                                                                 4                                        2 (15.4)
                                                                                 5                                       1 (7.7%)
                                                                                 6                                       1 (7.7%)
                                                                                 Total                                 13 (100%)




4                                                                           Original Article | Dermatol Pract Concept. 2024;14(1):e2024096
 Table 2. Trichoscopic Findings Encountered in                       Extension around the isthmus was seen in 1 case (2.7%).
          the Studied Cohort (n=100).                                Table 3 illustrates details of histopathological findings.
                                                                        PPS was significantly encountered in cases with skin type
   Trichoscopic       Number                          Number
      Finding           (%)            Score            (%)          III (p=0.001) and in females with Sinclair grade 3 (p=0.031).
 PPS (Frontal         50 (50%) Light                   25(50%)       Its absence was significantly associated with the absence
 and occipital)                     Moderate          18 (36%)       of yellow dots (p <0.001) and the PPS score significantly
                                                                     positively correlated with the yellow dots score (r=0.498,
                                    Dark                7 (14%)
                                                                     p<0.001). PPS was not significantly associated with PFI,
 PPS (Occipital            7 (7%) Light               5 (71.4%)
 only)                                                               PFF, perivascular infiltrate but it was significantly associ-
                                    Moderate          2 (28.6%)
                                                                     ated with the absence of melanophages (p=0.011) (Table 4,
                                    Dark                 0 (0%)
                                                                     Figures 5 , 6).
 Pigment              35 (35%) Scattered             23 (65.7%
 (honeycomb)                   (light brown)
 pattern                            Condensed       12 (34.3%)       Conclusion
                                    (brown)
 Yellow dots          33 (33%) Yellow               27 (81.8%)       In the studied cohort, PFI was present in 82.2% of all stud-
                                                                     ied biopsies with no significant difference between those
                                    Light brown       6 (18.2%)
                                                                     with and those without PPS indicating that PPS is not a re-
 Pin-point            24 (24%)
 white dots                                                          flection of the presence of PFI.
                                                                        Although PPS has been frequently reported in AGA
 White patches             4 (4%)
                                                                     with frequencies ranging from 31% to 90% [6,15–17], it
 Focal atrichia       26 (26%)
                                                                     has also been reported in other types of hair loss not asso-
PPS: Peripilar sign
                                                                     ciated with PFI such as telogen effluvium [4,16–18], anagen
                                                                     ­effluvium [19] as well as in normal people [20] indicating
                                                                     that there must be an explanation other than PFI for PPS.
                                                                        In an attempt to identify the relationship between PPS
                                                                     and other variables in AGA cases, we compared those with
                                                                     PPS and those without PPS as regards the demographic,
                                                                     ­clinical, trichoscopic and histopathological features studied
                                                                     in our cohort. Fitzpatrick’s skin type and the presence of
                                                                     yellow dots significantly influenced the presence of PPS. It
                                                                     was significantly encountered in skin type III compared to
                                                                     skin type IV, as was previously reported by Kibar et al. [20].
                                                                     This can be explained by the increased contrast between the

Figure 4. Trichoscopy showing PPS (red arrows); yellow dots (blue
                                                                     dark PPS and the lighter surrounding skin in skin type III.
arrows) and areas of focal atrichia (green circles) (x20).           This is compatible with the observation of Inui et al. [21] on



                       Table 3. Histopathological Findings in the Studied Biopsies (n=45).
                 Histopathological Finding                        Number (%)             Density/Grade             Number (%)
 Perifollicular infiltrate (PFI)                                  37 (82.2%)      Mild                              33 (89.2%)
                                                                                  Moderate                           4 (10.8%)
 Perifollicular (peri-infundibuar) fibrosis (PFF)                 28 (62.2%)      Mild                              25 (89.3%)
                                                                                  Moderate                           3 (10.7%)
 Perivascular infiltrate                                          42 (93.3%)      Mild                              37 (88.1%)
                                                                                  Moderate                           5 (11.9%)
                                                                                  Upper dermis only                 38 (90.5%)
                                                                                  Upper and mid-dermis                 4 (9.5%)
 Melanophages                                                       27 (60%)




Original Article | Dermatol Pract Concept. 2024;14(1):e2024096                                                                    5
           Table 4. Comparison Between Cases With and Cases Without Peripilar Sign (PPS)
                                                       PPS Present            PPS Absent
                                                        (50 cases)             (50 cases)             P-Value
Age                                                   36.24 ± 12.68          31.76 ± 9.92           0.106 (MW)
Gender                                 Female           45 (90.0%)            42 (84.0%)
                                                                                                    0.372 (χ2)
                                       Male              5 (10.0%)             8 (16.0%)
Occupation                             Indoor          50 (100.0%)            47 (94.0%)
                                                                                                    0.242(F)
                                       Outdoor              0 (0%)                 3 (6%)
Special habits of medical importance   Smoker               3 (6%)                7 (14%)
                                                                                                    0.182(χ2)
                                       Non-smoker         47 (94%)              43 (86%)
Fitzpatrick skin type                  III                27 (54%)              11 (22%)
                                                                                                    0.001(χ2)*
                                       IV                 23 (46%)              39 (78%)
Duration of hair loss                                   5.78 ± 5.33           4.36 ± 3.96           0.288 (MW)
Trichodynia                            Present            17 (34%)              17 (34%)
                                                                                                        1(χ2)
                                       Absent             33 (66%)              33 (66%)
Application of topical minoxidil       Present            11 (22%)              13 (26%)
                                                                                                    0.640(χ2)
                                       Absent             39 (78%)              37 (74%)
Application of topical steroids        Present              2 (4%)                 1 (2%)
                                                                                                        1(F)
                                       Absent             48 (96%)              49 (98%)
Use of hair dyes                       Present             5 (10%)              10 (20%)
                                                                                                    0.161(χ2)
                                       Absent             45 (90%)              40 (80%)
Use of hair straightening procedures   Present              1 (2%)                 2 (4%)
                                                                                                        1(F)
                                       Absent             49 (98%)              48 (96%)
Use of hair oils/creams                Present            46 (92%)              42 (84%)
                                                                                                    0.218(χ2)
                                       Absent               4 (8%)                8 (16%)
Use of hot hair styling devices        Present              4 (8%)                 4 (8%)
                                                                                                        1(F)
                                       Absent             46 (92%)              46 (92%)
Head covering                          Yes                44 (88%)              41 (82%)
                                                                                                    0.401(χ2)
                                       No                  6 (12%)                9 (18%)
UVR exposure                           Routine          50 (100%)               47 (94%)
                                                                                                    0.242(F)
                                       Excessive            0 (0%)                 3 (6%)
Females grade (Sinclair Scale)         2                12 (26.7%)            22 (52.4%)
                                       3                24 (53.3%)            12 (28.6%)
                                                                                                    0.031(F)*
                                       4                 8 (17.8%)                8 (19%)
                                       5                  1 (2.2%)                 0 (0%)
Males grade (Hamilton and Norwood      1                 1 (20.0%)                 0 (0%)
Classification)                        2                    0 (0%)                2 (25%)
                                       3/ 3 vertex         3 (60%)             3 (37.5%)
                                                                                                    0.322(F)
                                       4                    0 (0%)                2 (25%)
                                       5                    0 (0%)             1 (12.5%)
                                       6                   1 (20%)                 0 (0%)
Yellow dots                            Present            26 (52%)                7 (14%)
                                                                                                  <0.001 (χ2)*
                                       Absent             24 (48%)              43 (86%)
                                                      PPS Present           PPS Absent
                                                     (Subgroup A,          (Subgroup B,              p-value
                                                        n=22)                 n=23)
PFI                                    Present          17 (77.3%)            20 (87.0%)
                                                                                                    0.459 (F)
                                       Absent            5 (22.7%)             3 (13.0%)
PFF                                    Present          12 (54.5%)            16 (69.6%)
                                                                                                    0.299 (χ2)
                                       Absent           10 (45.5%)             7 (30.4%)


6                                                       Original Article | Dermatol Pract Concept. 2024;14(1):e2024096
                                                                             PPS Present              PPS Absent
                                                                            (Subgroup A,             (Subgroup B,                 p-value
                                                                               n=22)                    n=23)
 Perivascular infiltrate                           Present                      20 (90.9%)               22 (95.7%)
                                                                                                                                0.608 (F)
                                                   Absent                          2 (9.1%)                 1 (4.3%)
 Melanophages                                      Present                        9 (40.9%)              18 (78.3%)
                                                                                                                                0.011 (χ2)*
                                                   Absent                       13 (59.1%)                 5 (21.7%)

Chi square (χ2) test or Fisher’s Exact (F) test or non-parametric Mann-Whitney test (MW).
P-value is significant if <0.05*
Data is presented as mean ± SD or as number (%)
PPS: Peripilar sign PFI: Perifollicular infiltrate




Figure 5. AGA case with peripilar sign (PPS) and no perifollicular infiltrate (PFI). (a) Clinical picture: Sinclair hair density (grade 3).
(b) Trichoscopic examination (X20): hair shaft diameter diversity, PPS, and yellow dots. (c) Trichoscopic examination (X50 ): PPS (+++)
and yellow dots (+). (d) Photomicrograph showing no PFI in relation to upper segments of hair follicles (H&E original magnification X40).




Figure 6. AGA case with peripilar sign (PPS) and perifollicular infiltrate (PFI). (a) Clinical picture: Sinclair hair density (grade 3). (b) Tricho-
scopic examination (X20): hair shaft diameter diversity, PPS, and yellow dots. (c) Trichoscopic examination (X50): PPS (++) and yellow dots
(+). (d & e) Photomicrographs showing mild PFI related to the infundibula of hair follicles (H&E original magnification X100).


Original Article | Dermatol Pract Concept. 2024;14(1):e2024096                                                                                    7
Asian population and Chiramel et al. [22] on Indian popu-               3. Jain N, Doshi B, Khopkar U. Trichoscopy in alopecias: diagnosis
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                                                                        7. Tosti A. Androgenetic Alopecia. In: Dermoscopy of Hair and
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lated to low severity in male pattern AGA, but not correlated
                                                                           Brenn T, Lazar AJ, MacKee PH, Billings SD, eds. McKee’s
at all to severity of female pattern AGA. Such outcome would               ­Pathology of the Skin: With Clinical Correlations. Fifth edition.
indicate that this is not a consistent finding to depend upon.              Elsevier; 2018:1051-1128.
     We hypothesize that PPS is a form of dark color around            12. Chan YH. Biostatistics 102: quantitative data--parametric &
the follicular openings that appears more obviously in lighter              non-parametric tests. Singapore Med J. 2003;44(8):391-396.
                                                                       13. Chan YH. Biostatistics 103: qualitative data - tests of indepen-
skin types. It is known that ultraviolet rays stimulate inactive
                                                                            dence. Singapore Med J. 2003;44(10):498-503.
melanocytes in the outer root sheath [23] and this may ex-
                                                                       14. Chan YH. Biostatistics 104: correlational analysis. Singapore
plain PPS in AGA cases due to the increased effect of UVR                   Med J. 2003;44(12):614-619.
on the balding skin. Perifollicular infiltrate may stimulate           15. Karadağ Köse Ö, Güleç AT. Clinical evaluation of alope-
the melanocytes too [21]. Further studies using melanocyte                  cias using a handheld dermatoscope. J Am Acad Dermatol.
markers and Masson Fontana's stain are needed to further                    2012;67(2):206-214.
                                                                       16. Park J, Kim JI, Kim HU, Yun SK, Kim SJ. Trichoscopic Findings
verify the cause of this peri-follicular dark color.
                                                                            of Hair Loss in Koreans. Ann Dermatol. 2015;27(5):539.
                                                                       17. Varma K, Singh U, Kataria M. Trichoscopy in common
Limitations of the Study                                                    scalp ­alopecia: an observational study. Int J Res Dermatol.
• The lack of comparison with normal healthy controls or                    2020;6(3):361.
    patients with other non-scarring hair loss disorders rep-          18. Mani S, Manickam N, Gopalan K. Role of dermoscopy in the di-
                                                                            agnosis of alopecia. J Pak Assoc Dermatol. 2018;28(3):320-328.
    resents a limitation in this study.
                                                                       19. Malakar S, Mehta P, Malakar S. Trichoscopy in anagen ef-
• Not all patients consented for scalp biopsy.
                                                                            fluvium: Extensive peripilar sign. Our Dermatol Online.
                                                                            2017;8(4):493-494.
     PPS in AGA appears to be unrelated to PFI. Skin of color          20. Kibar M, Aktan Ş, Bilgin M. Scalp Dermatoscopic Findings in
conceals pigmented trichoscopic findings such as PPS and                    Androgenetic Alopecia and Their Relations with Disease S­ everity.
yellow dots which in turn should not be considered as diag-                 Ann Dermatol. 2014;26(4):478.
                                                                       21. Inui S, Nakajima T, Itami S. Scalp dermoscopy of androgenetic
nostic criteria for AGA in dark-skinned patients.
                                                                            alopecia in Asian people. J Dermatol. 2009;36(2):82-85.
                                                                       22. Chiramel M, Sharma V, Khandpur S, Sreenivas V. Relevance
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8                                                                           Original Article | Dermatol Pract Concept. 2024;14(1):e2024096
