Dermatology: Practical and Conceptual Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 1 Assessment and Validity of Trichoscopy for Eyebrow Involvement in Lichen Planopilaris and Frontal Fibrosing Alopecia: A Case-Control Study Awatef Kelati1,2, Wassim Halli 1, Soumiya Chiheb1 1 Dermatology Department, University Hospital Cheikh Khalifa, and the University Hospital Mohammed VI Faculty of Medicine, Mohammed VI University of Health and Sciences (UM6SS), Casablanca, Morocco 2 Non-invasive Skin Imaging Group of the French Society of Dermatology Key words: Trichoscopy, Dermoscopy, Eyebrows, Hair disorders, Madarosis, Validity, Lichen planopilaris, Frontal fibrosing alopecia, Acquired eyebrow disorders Citation: Kelati A, Halli W, Chiheb S. Assessment and Validity of Trichoscopy for Eyebrow Involvement in Lichen Planopilaris and Frontal Fibrosing Alopecia: A Case-Control Study. Dermatol Pract Concept. 2024;14(4):e2024277. DOI: https://doi.org/10.5826/dpc.1404a277 Accepted: July 28, 2024; Published: October 2024 Copyright: ©2024 Kelati 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: Kelati Awatef, Email: akelati@um6ss.ma/awatkelati@gmail.com Introduction: Few publications are available on eyebrow trichoscopy in patients with alopecia areata and frontal fibrosing alopecia (FFA). Objective: To investigate the validity of using trichoscopy to examine eyebrow involvement in patients with lichen planopilaris (LPP) and FFA. Methods: In this case-control study, 109 patients with eyebrow involvement in LPP and FFA (cases) and with acquired hair disorders of the eyebrows (controls) were included. Results: Trichoscopy was highly specific and sensitive for the diagnosis of LPP and FFA. Trichoscopic features significantly associated with LPP were peripilar scaling, peripilar pigmentation, broken hairs, peripilar white halos, diffuse empty follicles, and vellus hair. Localized peripilar erythema and empty follicles were significantly associated with the diffuse form of LPP and the zigzag type of FFA. Yellow dots, dystrophic hairs, hair regrowth in different directions, and diffuse empty follicles were associated with LPP activity and FFA severity. Limitations: The retrospective nature of the statistical analysis. Conclusions: Trichoscopy is a valid tool for evaluating eyebrow involvement in LPP and FFA. Thus, it could help increase the diagnostic accuracy and predict the prognosis of eyebrow hair loss at an early stage. ABSTRACT 2 Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 Introduction Eyebrows are short terminal hairs that serve important bio- logical and social functions, especially eye protection, non- verbal expression, and gender definition, in addition to their crucial role in facial aesthetics [1]. Therefore, hair disor- ders at this location may have functional and psychological effects. Hair loss is the most frequent eyebrow disorder. It can be classified as scarring or non-scarring alopecia and may pres- ent as an isolated finding or as the presenting manifestation of an underlying systemic or hair disease. Thus, its etiolo- gies are varied, including autoimmune (alopecia areata [AA] and frontal fibrosing alopecia [FFA]), infectious (leprosy, cutaneous syphilis, and tinea), neoplastic (hematologic ma- lignancies), nutritional (zinc deficiency), traumatic (tricho- tillomania), endocrinologic (hypothyroidism), and genetic (keratosis follicularis spinulosa decalvans) conditions [2]. Given the extensive breadth of etiology and the impor- tance of the eyebrows in many functional and cosmetic roles, a prompt, early, accurate diagnosis is mandatory as the first step in clinical and therapeutic management [2]. Unfortu- nately, few studies have focused on the diagnosis and man- agement of eyebrow disorders. In the literature, most hair disorders affecting the eye- brows, especially those causing hair loss, first affect the lateral third (tail), which may be explained by the thinner nature and lower density of the hairs (shortest anagen and lowest follicular stem cell proliferation level) in comparison with those of other eyebrow hairs [1,3]. Hair loss in this segment may result from repeated itching and rubbing in inflammatory dermatoses, such as atopic dermatitis, which is known as Hertoghe’s sign [4]. Involvement of the other segments of the eyebrows has also been reported in AA, FFA, and trichotillomania [4]. Trichoscopy is not only a good noninvasive tool for scalp alopecia and hair disorders but can also be of great help in diagnosing hair loss or hair diseases of the eyebrows at an early stage. However, studies using this tool in this context are rare, and its use has only been reported for FFA, AA, and trichotillomania. In this study we aimed to describe clinical and tricho- scopic patterns of hair disorders of the eyebrows and eye- brow involvement in lichen planopilaris (LPP) and FFA, to correlate trichoscopic findings with the epidemiological and clinical characteristics of LPP patients, and to investigate the validity of using trichoscopy to evaluate these acquired eye- brows disorders. Methods This study was approved by the ethics committee of the Mohammed VI University of Health Sciences of Casablanca. We collected dermoscopic images of the eyebrows of 109 patients with acquired hair disorders of the eyebrows, either in isolation or associated with hair disorders affecting the scalp, during dermatology consultations between Sep- tember 2022 and November 2023. Cases were patients who had eyebrow involvement in LPP and FFA, while controls were patients with other ac- quired hair disorders of the eyebrows. Clinical and paraclinical sociodemographic data were retrospectively extracted from medical records. Eyebrow trichoscopic analysis was performed in patients with hair loss regardless of whether the eyebrow was clinically af- fected or in patients with visible eyebrow disorders (hair loss, erythema, or scaling). To analyze the entire eyebrow on each side, we divided the eyebrow into three segments (the head, body, and tail) using lines running perpendicular to the medial and lateral canthi [1,3]. The severity of eyebrow hair involvement was as- sessed based on the percentage of the area depilated per dermoscopic field (<50% or ≥50%), the areas of the eye- brows affected, and the extent of hair damage based on the clinician-reported outcome (ClinRO) for eyebrow loss which was describe for AA [5]. The ClinRO was rated on a scale of 0 (no involvement) to 3 (complete loss). Diagnoses of non-cicatricial alopecia (AA or trichotillo- mania) were established based on detailed medical history, clinical examination, and scalp trichoscopy. Cicatricial alo- pecia was confirmed based on histopathological analysis of the scalp. Biopsy of the eyebrows was not performed. Am- biguous cases were excluded from the study. Patients with a history of recent eyebrow plucking were advised to return for a trichoscopic examination within one month. For LPP, disease activity assessment (scalp involvement) was performed using the LPP activity index (LPPAI) [6]. For FFA, we used the severity grade (the V-grade classification) described by Vañó et al. and categorized patients as having either mild (I-II) or severe (III-V) FFA [7]. In every case, dry trichoscopy with or without trichos- copy with immersion fluid from the eyebrow area was performed using a DermoLite 4 or HeineDelta 30 digital dermoscope. All trichoscopic images were blindly analyzed by two independent evaluators for the presence of specific abnormalities in the hair shaft structure and skin surface. Data extraction was performed using Excel. Data were analyzed using IBM SPSS Statistics version 25 software. De- scriptive statistics are expressed as means and percentages. Differences in the incidence rates of various trichoscopic fea- tures according to the epidemiological and clinical charac- teristics of the patients were examined using the chi-square test. The results were considered statistically significant if the p-value was <0.05. Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 3 Results Clinical Characteristics A total of 109 patients were examined, and 1,408 images were evaluated. The average patient age was 42.92 ± 17.47 years, patients aged 31–45 years were the most prevalent (27.52%), and females were predominant (66.97%). LPP and FFA (cases) represented 52.3% of all the cases (57 patients), including the diffuse clinical form (39 patients) and 11 patients with FFA. Scalp involvement was noted in all patients, and beard involvement occurred in 10 male pa- tients. Apart from patients with FFA, Grade I hair line reces- sion was noted in 29 patients with LPP (63%). The control group included other causes of hair loss, such as AA in five patients (4.9%), folliculitis decalvans (FD), trichotillimania, and anagen effluvium after chemo- therapy in three patients each (2.75%), and infiltrative basal cell carcinoma in one patient, and eyebrow disorders with- out hair loss such as seborrheic dermatitis (SD; 11 patients, 10.09%), psoriasis (seven patients, 6.42%), chronic eczema (five patients, 4.59%), rosacea (five patients, 4.59%), lupus discoid (four patients, 3.67%), demodicidosis (three patients, 2.75%), and sarcoidosis (two patients, 1.8%). Female sex was significantly associated with the diagno- sis of LPP and FFA, lupus and AA (P <0.001). Alopecia of the eyebrows was not clinically visible in the majority of patients (66 patients). Clinical visibility of eye- brow disorders was significantly associated with FFA diag- nosis, active LPP (tail involvement), and SD (P=0.005). Trichoscopic Findings of the Eyebrows (all diagnoses included) (Figures 1-2) Peripilar erythema was the most frequent trichoscopic sign, with 93 patients having localized peripilar erythema (<50%) and only six patients having diffuse peripilar erythema; for ten patients, erythema was replaced by peripilar pigmenta- tion, including all eight patients (7.34%) with a dark photo- type (V–VI) (Table 1). Vellus hair and empty follicles were observed in all pa- tients with AA, while yellow dots were found three patients and exclamation marks and circular pigtail hairs in one patient. Trichoscopy of eyebrow hairs involved in lupus discoid identified localized peripilar scaling and peripilar white ha- los in all patients, localized peripilar erythema in 75% of patients. Correlations of Trichoscopy in Cases and Controls Trichoscopic features significantly associated with LPP were peripilar scaling (P<0.001), peripilar pigmentation (P=0.003), broken hairs (P<0.001), peripilar white halos (P=0.011), diffuse empty follicles (P=0.038), and vellus hair (P=0.048). Figure 1. Trichoscopic image of the body (A) of the eyebrow of a dark-skinned patient with LPP. Peripilar pigmentation (orange ar- row), peripilar scaling (blue arrow), vellus hair (blue circle), peripilar white halos (white arrow), and empty follicles (green arrow). Figure 2. Trichoscopic image of the head of the eyebrow of a patient with diffuse LPP. Peripilar erythema (red arrow), peripilar scaling (blue arrow), vellus hair (blue circle), peripilar white halos (white arrow), and empty follicles (green arrow). 4 Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 The disease activity of LPP and FFA severity were sig- nificantly associated with clinically visible eyebrow involve- ment (P=0.012), an affected area of >50% (P<0.001), and trichoscopic features, such as yellow dots (P=0.024), dystro- phic hairs (P=0.015), diffuse pattern of regrowth in different directions (P=0.011), and diffuse empty follicles (P=0.002). Peripilar erythema and red dots were associated with phototypes III and IV (P<0.001 and P=0.027, respectively), whereas peripilar pigmentation was associated with very dark phototypes (V and VI; P<0.001). Vellus hair and empty follicles were significantly asso- ciated with clinically visible eyebrow loss (P=0.021 and P<0.001, respectively). Facial involvement in FFA (facial papules) was associ- ated with trichoscopic findings in the eyebrows: yellow dots (P=0.006), red dots (P<0.001), and broken hairs (P=0.019). Trichoscopy was highly specific and sensitive for diag- nosing LPP and its variants, including FFA (Table 3). Discussion Available data concerning trichoscopy of the eyebrows are rare; few publications have been reported on FFA and AA, and no data are available concerning LPP. In addition, the distinction between LPP and FFA has been described in dif- ferent body regions, especially the scalp, beard, and body hair [8]; however, no comparison has been performed in the eyebrows. In this study, no comparison between the two diagnoses was performed for the following reasons: FFA is Concerning chronic eczema, significant associations were observed for certain features, including dystrophic hairs (P=0.019), Focal hair regrowth in different directions (P=0.030), and other trichoscopic signs (P=0.000), such as crusts, pustules, and erosions. Diffuse peripilar erythema (P=0.017) was the only sign significantly associated with psoriasis. No significant associations were found between trichos- copy and other diagnoses, particularly SD, lupus, and rosacea. Trichoscopy of the Eyebrows in Patients with LPP and its Variants (Table 2) The majority of patients with LPP had affected hairs in the tail (41), with isolated tail involvement in 11 patients. Eye- brow examination was not the reason patients sought con- sultations, and the majority of patients ignored eyebrow involvement; thus, we were unable to determine whether eyebrow loss was an initial clinical manifestation of the disease. The area affected by the eyebrows was <30% in 47 patients (82.4%). Localized peripilar erythema, peripilar pigmentation, empty follicles, localization to the tail, and diffuse eyebrow involvement with an area of <30% were significantly associated with the diffuse clinical form of LPP (P=0.028, P=0.04, P<0.001, P=0.016, and P=0.001, respec- tively). Localized peripilar erythema and empty follicles were also associated with the zigzag variant of FFA (P=0.028 and P<0.001, respectively). Table 1. Analysis of the Trichoscopic Findings of the Eyebrows of Cases and Controls. Trichoscopic signs Number Percentage Significant association with a diagnosis p-value Peripilar erythema 99 90.8% Diffuse erythema (≥50%) 6 5.50% Psoriasis 0.017 Localized erythema (<50%) 93 85.32% Peripilar pigmentation 8 7.3% Lupus and LPP 0.033 Peripilar scaling (PPS) 101 92.7% Diffuse PPS (≥50%) 2 1.83% Psoriasis 0.001 Localized PPS (<50%) 99 90.83% LPP/FFA <0.001 Vellus hair 89 81.65% LPP/FFA 0.048 Peripilar white halo 83 76.15% LPP/AFF 0.011 Empty follicles 81 74.3% LPP/FFA 0.038 Eyebrow regrowth in different directions 71 65.14% Eczema 0.030 Dystrophic hairs 56 51.38% Eczema 0.019 Yellow dots 32 29.36% Red dots 26 23.85% Broken hairs Diffuse Localized 28 25 3 25.69% 22.9% 2.7% Trichotillomania (broken at different lengths) LPP <0.001 Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 5 involvement in LPP was clinically invisible in the majority of our patients and was more frequent in the tail of the eye- brows; it was significantly associated with trichoscopic fea- tures such as peripilar scaling, peripilar pigmentation in the dark phototype, broken hairs, peripilar white halos, vellus hair, and diffuse empty follicles. Trichoscopy was also correlated to the clinical variants of LPP; the recently described diffuse clinical variant of LPP [10] has been significantly associated with trichoscopic findings, such as localized peripilar erythema and empty follicles, which were also significantly linked to the zigzag variant of FFA. This is an additional important result for an early considered a clinical variant of LPP in many publications [9], LPP is more prevalent than FFA, FFA grade I is associated with the diffuse forms of LPP in many patients, and tricho- scopic features were similar according to our evaluators. We therefore considered both diagnoses in the same group of cases. Although eyebrow hair loss was not clinically visible in most our patients, trichoscopy was a specific and sensitive tool that increased the diagnostic accuracy of eyebrow LPP and FFA. Trichoscopic features of autoimmune diseases of the eyebrows are often subtle at the beginning. Eyebrow Table 2. Descriptive Analysis of Trichoscopy of the Eyebrows in Cases and Controls. Cases: LPP/AFF (57) Controls (other diagnoses: 52) Mean age 39.1+/-17.2 46.1+/-18.3 Qualitative variables Number Percentages Number Percentages Sex F: 41 M: 15 73.2 26.8 F: 32 M: 20 61.5 38.4 Family history of the disease 3 5.2 Facial involvement 6 FFA 11.1 2 3.8 Clinically visible Tail Diffuse 11 8 3 19.3 72 27.3 32 14 18 61.5 26.9 34.6 Peripilar erythema Localized Diffuse 53 49 4 92.9 85.9 7 49 47 2 94.2 90.3 3.8 Peripilar pigmentation 3 5.2 5 9.6 Peripilar scaling Localized Diffuse 56 55 2 98.2 96.5 3.5 47 46 1 90.3 88.4 1.9 Peripilar white halo Localized Diffuse 47 4 43 82.5 7 75.4 22 20 2 42.3 38.4 3.8 Vellus hair 51 89.5 41 78.8 Yellow dots 17 29.8 12 23 Red dots 10 17.5 12 23 Broken hairs 11 19.3 13 25 Dystrophic hairs 28 49 26 50 Regrowth in different direction (RDD) 33 57.9 33 63.4 Diffuse RDD Focal RDD 8 FFA 25 14 43.8 0 33 0 63.4 Empty follicles Localized Diffuse 47 43 4 82.5 75.4 7 30 57.6 Table 3. Validity of Trichoscopy in the Evaluation of Eyebrow Involvement in LPP and its Variants. Diagnosis Sensibility Specificity Positive Predictive Value Negative Predictive Value Cases (LPP and variants) 87.5% 98.08% 87.5% 98.08% Controls 44.74% 70.97% 48.57% 67.69% 6 Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 Conclusions In this pilot study, trichoscopy was a valid tool for evaluat- ing eyebrow involvement in LPP and FFA. Thus, it could be of great help in increasing the diagnostic accuracy and pre- dicting the prognosis of eyebrow hair loss at an early stage. Early diagnosis may be performed by examining the tail of the eyebrows in LPP patients, which contains trichoscopic features such as peripilar scaling, peripilar erythema, broken hairs, peripilar white halos, diffuse empty follicles, and vellus hair. Yellow dots, dystrophic hairs, diffuse regrowth in differ- ent directions, and diffuse empty follicles were significantly associated with active and severe forms of LPP and FFA. Acknowledgments: We are grateful to Philippe Bahadoran, president of the ICNI groupe of the French Society of Dermatology, for his help in improving the manuscript. References 1. Mumford BP, Eisman S, Yip L. Acquired causes of eyebrow and eyelash loss: A review and approach to diagnosis and treatment. Australas J Dermatol. feb 2023;64(1):28-40. DOI:  10.1111 /ajd.13947 2. Nguyen B, Hu JK, Tosti A. Eyebrow and Eyelash Alopecia: A Clinical Review. Am J Clin Dermatol. Jan 2023;24(1):55-67. DOI: 10.1007/s40257-022-00729-5 3. Suchonwanit P, Thammarucha S. Eyebrow growth pattern anal- ysis in patients with eyebrow hypotrichosis after receiving top- ical treatment: A retrospective study. J Cosmet Dermatol. Jun 2020;19(6):1404-8. DOI: 10.1111/jocd.13167 4. Velez N, Khera P, English JC. Eyebrow loss: clinical re- view. 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Lichen planopilaris and frontal fibrosing alopecia: review and update of diagnostic and diagnosis of these underdiagnosed clinical subtypes of LPP and FFA. Another interesting finding of this study was that clini- cal visibility of the eyebrows involvement was significantly linked to advanced active disease with an affected area of >50% (P<0.001), which confirms the crucial role of an early diagnosis based on trichoscopy, since in reported studies of FFA, trichoscopic analysis was rather performed in clinically visible madarosis, with bilateral partial or complete eyebrow involvement [4,11], or in isolated forms of FFA [12]. Affected eyebrows in FFA often appear to be non- inflammatory and non-scarring clinically [13] and demon- strate non-scarring features on trichoscopy. Similarly, a cohort of 151 patients with FFA had findings of non- cicatricial al- opecia including short vellus hairs, hair growing in different directions, tapered and broken hairs, dystrophic hairs, black dots, red dots, yellow dots, and multiple pinpoint dots [2]. This fact explains the reversibility of some eyebrow loss in FFA [2,14]. Also, signs of cicatricial hair loss including white cicatricial areas, white dots, pili torti, and visualization of hair bulbs that reflect skin atrophy in advanced FFA have been described [8,11,14]. Signs like dystrophic hairs and hairs growing in different directions were considered more specific trichoscopic findings of eyebrow FFA, which can be useful in diagnosing patients with isolated eyebrow loss [11,12]. However, the lack of a control group in these studies makes it difficult to draw conclusions, a better trichoscopic characterization is then mandatory as we have found that focal regrowth in different directions was also noticed in the control group of inflammatory acquired eyebrow disorders. Diffuse hair growth in different directions was signifi- cantly associated with severe and active LPP and FFA in our study, which has also been described in the literature, in addition to pili torti as early markers of fibrosis; and an indicator of a worse prognosis and a poor response to treat- ment (11,15). In contrast, the presence of red dots may be a favorable prognostic factor for eyebrow regrowth [2]. Diffuse erythema has been reported as a nonspecific trichoscopic feature in patients with AA and FFA [11]. This was identified in different diagnosis cases and controls in this study and was significantly related to eyebrow psoriasis. Study Limitations The limitations of this study were the retrospective nature of the statistical analysis and the small number of patients with each diagnosis in the control group. In addition, the controls were not matched for age or sex. Original Article | Dermatol Pract Concept. 2024;14(4):e2024277 7 13. Chew AL, Bashir SJ, Wain EM, Fenton DA, Stefanato CM. Expanding the spectrum of frontal fibrosing alopecia: a uni- fying concept. J Am Acad Dermatol. oct 2010;63(4):653-60. DOI: 10.1016/j.jaad.2009.09.020 14. Anzai A, Pirmez R, Vincenzi C, Fabbrocini G, Romiti R, Tosti A. Trichoscopy findings of frontal fibrosing alopecia on the eyebrows: A study of 151 cases. J Am Acad Dermatol. Nov 2021;85(5):1130-4. DOI: 10.1016/j.jaad.2019.12.023 15. Ferrari B, Vincenzi C, Tosti A. Pili Torti as a Sign of Eyebrow Involvement in Frontal Fibrosing Alopecia. Skin Appendage Disord. Nov 2019;5(6):393-5. DOI: 10.1159/000502059 therapeutic features. An Bras Dermatol.May 2022;97(3):348-57. DOI: 10.1016/j.abd.2021.08.008 10. Starace M, Orlando G, Alessandrini A, Baraldi C, Bruni F, Piraccini BM. Diffuse variants of scalp lichen planopilaris: Clin- ical, trichoscopic, and histopathologic features of 40 patients. J Am Acad Dermatol. Dec 2020;83(6):1659-67. DOI: 10.1016 /j.jaad.2019.11.006 11. Waśkiel-Burnat A, Rakowska A, Kurzeja M, et al. The value of dermoscopy in diagnosing eyebrow loss in patients with alopecia areata and frontal fibrosing alopecia. JEADV. Jan 2019;33(1):213-9. DOI: 10.1111/jdv.15279 12. Atış G, Sarı AŞ, Güneş P, Sönmez C. Isolated hair loss on the eye- brow: five cases with trichoscopic features. An Bras Dermatol. 2022;97(3):372-5. DOI: 10.1016/j.abd.2021.04.015