Erratum.

Extensive facial scarring after ablative laser resurfacing in a patient with frontal fibrosing alopecia

Lichen planopilaris (LPP) is a form of scarring alopecia associated with progressive, permanent hair loss. Symptoms range from burning pain to itching, also carrying substantial psychological morbidity. Yet, disease characteristics, pathophysiology, and effective treatment data are limited, making treatment a challenge. To describe the prevalence and dermatologist-prescribed treatment patterns of LPP among US adults. This cross-sectional study used the Explorys database. The prevalence analysis used a 15% random sample and identified US adults with LPP diagnoses between 2017 and 2019. The LPP treatment analysis included all patients with LPP diagnoses between 2016 and 2020 and a dermatologist encounter in the first year after diagnosis. Data were analyzed from January 2023 to April 2023. The main outcomes of the prevalence analysis were the crude and standardized prevalence estimates of US adults with LPP across age, sex, and racial groups. The main outcomes of the treatment analysis were the frequency of LPP treatments within 1 year of diagnosis, and the number of patients who continued treatment beyond 1 year, switched treatments, and combined treatments. Among 1 466 832 eligible patients analyzed for prevalence, 241 patients had an LPP diagnosis (222 [92.1%] female; median [IQR] age, 64 [54-73] years). Standardized overall prevalence was 13.4 per 100 000 (95% CI, 11.7-15.1). In the treatment analysis, 991 patients had an LPP diagnosis (907 [91.5%] female; median (IQR) age, 60 [47-69] years). Most received at least 1 type of medication (635 [64.1%]), most frequently intralesional corticosteroids (370 [37.3%]) and topical corticosteroids (342 [34.5%]), followed by doxycycline (104 [10.5%]) and hydroxychloroquine (72 [7.3%]). Treatment continued beyond 1 year in 71 of 200 patients (35.5%) prescribed intralesional corticosteroids and 7 of 29 patients (24.1%) prescribed hydroxychloroquine. Treatment switching at 1 year occurred in 32 of 254 patients (12.6%) first prescribed an intralesional corticosteroid and in 44 of 194 (22.7%) first prescribed a topical corticosteroid. Combinations of 2 or 3 treatment types were given to 137 (13.8%) and 74 (7.5%) patients, respectively. This cross-sectional study reported prevalence and treatment patterns for US adults with LPP in a representative sample. Most patients with LPP received treatment, and many received multiple treatment types and switched treatments, suggesting further research into medication selection offers clinical benefit.

Lichen planopilaris (LPP) is a scarring alopecia rarely described in men. To investigate the clinical and histopathologic features of LPP in men. We performed a retrospective cohort study of male patients with LPP seen at Mayo Clinic between 1992 and 2016. Nineteen men with biopsy-confirmed LPP were included. The disease most commonly presented with diffuse (42.1%) or vertex scalp (42.1%) involvement. None of the patients had eyebrow or body hair involvement. Perifollicular erythema (94.7%) and pruritus (57.9%) were the most frequent clinical findings. Androgenetic alopecia (AGA) co-occurred in 26.3% of patients. Mucosal lichen planus was found in four patients (21.1%). Thyroid disease occurred in three patients (15.8%). Disease improvement (47.3%) occurred with combination topical and systemic therapy, topical clobetasol monotherapy, and minocycline monotherapy. LPP in men has similar clinical and histologic presentations as reported in women. Nonscalp hair loss appears less likely in men with classic LPP than reported in men with frontal fibrosing alopecia, while mucosal lichen planus and thyroid disease appear to be more common in classic LPP. Men with AGA can present with new-onset concomitant LPP. Limitations included small study size, variable follow-up, and lack of standardized clinical assessment due the study's retrospective nature.

Lichen planopilaris (LPP) is a rare form of cicatricial alopecia that has occasionally been reported in children. Because of the limited number of patients reported, little information is available about demographic characteristics, clinical presentation, or treatment options for these patients. A retrospective chart review of LPP cases in patients under 18 years of age from 1976 to 2013 was performed to further define clinicopathologic features of pediatric LPP. Four pediatric LPP patients ages 13 to 16 years were identified (three male, one female). One patient had scalp pruritus and one had other cutaneous findings of lichen planus (LP). Perifollicular scale and scarring were the most common physical examination findings, although changes mimicking those of alopecia areata were observed. Three patients were treated with topical or intralesional steroids. One patient was treated with minocycline. Histopathologic findings included perifollicular interface and perifollicular fibrosis in all cases. There was focal interfollicular interface in two cases and mild dermal mucin in one case. LPP is exceedingly rare in children. It may be misdiagnosed as alopecia areata in children because of the lack of symptoms and other features of LP. There should be a high index of suspicion for LPP in children with alopecia that is unresponsive to standard treatment or who have findings that are atypical for more common childhood alopecias.

Background: Lichen planopilaris (LPP) manifests as uni or multifocal patches of scarring alopecia across the scalp. Its symptoms include pruritus, trichodynia, and burning. Trichoscopy is a critical tool for early disease detection. In African descendants, LPP poses additional diagnostic challenges, given the black scalp peculiarities. These specific features include lower hair density, slower growth, and structural differences, compared to Caucasians. Moreover, the healthy black scalp may show distinctive features such as a honeycomb-pigmented network and sparse pinpoint white dots. Summary: In individuals of African descent, the most prevalent scarring alopecia is Central Centrifugal Cicatricial Alopecia, an important differential diagnosis for LPP in this population. LPP trichoscopy in the black scalp reveals unique features such as perifollicular erythema in the early stages, which often manifests as hyperpigmentation. This study aimed to review the literature on trichoscopy findings in LPP on black scalp categorizing them into distinct stages and highlighting their unique yet understudied characteristics. Key Messages: Despite not being as prevalent as nonscarring alopecias and not so frequent in the black scalp, LPP’s aesthetic and devastating psychosocial impact raise concerns. Therefore, early recognition is paramount to halt the progress of LPP, mitigate its psychosocial impact, and prevent misdiagnosis.

When lichen planus involves the scalp, it is known as lichen planopilaris, and when it involves the eye, it is known as ocular lichen planus; both are rare. Early detection and targeted therapy are crucial in preventing hair loss and scarring conjunctivitis. Little is known regarding appropriate treatment for lichen planopilaris. The objective of this case study is to present a new case of pediatric ocular lichen planus and lichen planopilaris and to identify all reported cases of pediatric lichen planopilaris, highlighting disease involvement, treatment, and response to treatment.

Histopathologic differentiation of lichen planopilaris (LPP) and discoid lupus erythematosus (DLE) as two common causes of primary cicatricial alopecias remains challenging. We performed a histopathologic study on a case series of LPP and DLE specimens to investigate the number, distribution, and morphology of mast cells as indices for differentiation of these two entities. H&E investigation and Giemsa staining for the detection of mast cells was performed. A total of 74 cases comprising 50 cases of LPP and 24 cases of DLE were assessed. The mean mast cell count and percentage were significantly higher in LPP group (p < 0.001). Mean degranulated mast cell count and the mean intact mast cell count were also significantly higher in LPP patients (p < 0.001). Most of the specimens, 58 (78.4%), showed both perifollicular and perivascular distribution of mast cells without significant difference between two groups. The morphology of mast cells was predominantly round-oval in 85.5%, predominantly fusiform in 13.5% with more frequent fusiform morphology in DLE group. The mast cell count detected by Giemsa staining could assist pathologists in distinguishing between LPP and DLE.

Lichen planopilaris (LPP) is an inflammatory cicatricial alopecia for which many different therapies are attempted with varying success. The Janus kinase (JAK) inhibitor, tofacitinib, has been shown to be effective in treating the noncicatricial alopecia, alopecia areata. As in alopecia areata, upregulation of interferon and JAK signaling may play a role in LPP. We retrospectively reviewed the cases of 10 patients with recalcitrant LPP who were treated with oral tofacitinib. Patients received oral tofacitinib 5 mg twice or three times daily for 2–19 months as either monotherapy or adjunctive therapy to other ongoing treatments including intralesional triamcinolone, hydroxychloroquine, and tacrolimus ointment. Eight patients had clinical improvement in LPP with tofacitinib as either monotherapy (4/10) or adjunctive therapy (4/10). LPP Activity Index (LPPAI) before and after treatment was measured in seven patients and was significantly different (6.22 before treatment, 3.08 after treatment; p value = .0014). Reduction in LPPAI ranged from 30 to 94%. One patient complained of 10 pound (4.5 kg) weight gain after 12 months on tofacitinib. No other adverse effects were reported. Treatment with oral tofacitinib either as monotherapy or adjunctive therapy can lead to measurable improvement in recalcitrant LPP.

Focal and diffuse fibrosing alopecias: Classical lichen planopilaris, frontal fibrosing alopecia, fibrosing alopecia with a pattern distribution, cicatricial pattern hair loss, and lichen planopilaris diffuse pattern

Lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA) are lymphocytic scarring alopecias affecting primarily the scalp. Although both diseases may share some clinical and histopathological features, in the last decade, FFA has become an "epidemic" particularly in Europe, North and South America with unique clinical manifestations compared to LPP, thus, raising the idea that this disease may have a different pathogenesis. Symptoms such as scalp burning, pruritus or pain are usually present in both diseases, suggesting a possible role for nerves and neuropeptides in the pathogenesis of both diseases. Based on some previous studies, neuropeptides, such as substance P (SP) and calcitonin gene-related peptide (CGRP), have been associated with lipid metabolism and many chronic inflammatory disorders. In this study, we asked if these neuropeptides are associated with LPP and FFA scalp lesions. Alteration in the expression of SP and CGRP in affected and unaffected scalp skin from patients with both diseases was found with examination of sections using immunohistochemical techniques and confocal microscopy. We then quantitatively assessed and compared SP and CGRP expression from control, LPP and FFA scalp biopsies. Although LPP and FFA share similar histopathologic findings, opposite results were found in affected and unaffected scalp in the ELISA tests, suggesting that these diseases may have different pathogenic mechanisms. We also found presence of histopathological inflammation irrespective of evident clinical lesions, which raises the possibility that both diseases may be more generalized processes affecting the scalp.

Lichen Planopilaris (LPP) is a lymphocyte-mediated scarring alopecia characterized by progressive follicular destruction and fibrosis. In this clinical trial, patients with biopsy proven LPP were treated with deucravacitinib (an oral inhibitor of tyrosine kinase 2 (TYK2)) 6 mg BID for 24 weeks (NCT-06091956). Bulk and single-cell RNA sequencing was performed on paired pre- and post-treatment scalp biopsies from baseline and week 4. Patients (N=10) demonstrated improvements in PGA (88.9%, p=0.008), LPPAI (-2.3 points, SD 1.1, p=0.002) and Skindex-16 (-21.0 points, SD 22.1, p=0.014) scores at week 24. Bulk transcriptomic analysis of untreated LPP revealed upregulation of type I Interferon (IFN)-stimulated genes and pathways related to inflammation, immune activation, keratinization, and extracellular matrix remodelling, with downregulation of immune and inflammatory pathways following treatment. Single-cell RNA-seq of LPP was characterized by enrichment of CD8+GZMK+ T cells which showed downregulation of T-cell receptor signaling as well as antiviral pathways with treatment. Basal keratinocytes exhibited reduced cytokine and interferon signaling and decreased communication with NK cells following treatment. CCL19+ fibroblasts were prominent in untreated disease was attenuated after treatment, with downregulation of type I IFN signaling. Selective TYK2 inhibition with deucravacitinib effectively suppresses these inflammatory circuits in LPP and represents a promising therapeutic strategy.

Background: Classic lichen planopilaris (LPP) is a patchy form of primary lymphocytic cicatricial alopecia localized on the vertex of the scalp. It is important, however, to be aware of other, less recognized presentations that may be missed without dermatoscopy and pathology. Methods and Results: We report 26 patients with LPP presenting with subtle erythema and scaling colocalized in the area of patterned thinning (androgenetic alopecia, AGA). All patients had been treated for seborrheic dermatitis in the past. Dermatoscopy showed the presence of 2-4 hairs emerging as a tuft from the same ostium surrounded by erythema, peripilar casts and interfollicular scaling associated with hair miniaturization. Histopathology obtained from those areas corresponded to LPP with concomitant follicular miniaturization. Conclusion: Subtle or focal cases of LPP may be missed for seborrheic dermatitis when overlapping with AGA. Dermatoscopy-guided biopsy from the affected scalp is the best approach to make a timely diagnosis. This is particularly important in patients with AGA evaluated to undergo hair transplantation, as active LPP is a contraindication for these patients.

Background Lichen planopilaris (LPP) is a form of autoimmune scarring alopecia with unknown etiology. Androgenic hormones may have a role in progression of LPP especially in menopausal women which could be associated with hirsutism. Therefore, we investigated the frequency of hirsutism as one of the clinical manifestations of androgen excess in women with LPP. Patients and methods This cross-sectional study was done during 5 years on 60 female LPP patients. Patients’ data were age, age-onset of LPP, menstrual status, body mass index (BMI), presence or absence of hirsutism, age-onset and location of hirsutism and history of nonfollicular lichen planus. Results Patients’ mean age was 46.53±10.03 years. Mean of age-onset of LPP in women was 41.35±10.48 years. Hirsutism was detected in 28.3% of cases. The mean of age-onset of LPP was 30.47±9.11 in women with hirsutism. Less than half of LPP patients (48.3%) were nonmenopausal women, of whom 41.4% had irregular menstrual periods. Overweight and obesity was detected in 43 (43.71%) of LPP cases. Age-onset of LPP in menopausal women was significantly higher than nonmenopausal women (P &lt;0.001). Frequency of obesity in the menopausal and nonmenopausal groups was not significantly different. Conclusion More than a quarter of LPP patients had hirsutism. Due to high frequency of hirsutism in Iranian women, our findings do not show higher frequency of hirsutism in LPP cases compared with other women.

Androgenetic alopecia is characterized by a defined area of progressive nonscarring alopecia. The clinical and histological findings in 15 women and 4 men with progressive scarring alopecia in a pattern distribution were studied. The results were evaluated and compared with clinicopathologic entities that feature scarring of the central scalp area, specifically, lichen planopilaris, pseudopelade, and follicular degeneration syndrome. Patients developed progressive fibrosing alopecia of the central scalp, without the multifocal areas of involvement typical of lichen planopilaris and pseudopelade. Perifollicular erythema, follicular keratosis, and loss of follicular orifices were limited to a patterned area of involvement. Biopsy specimens of early lesions demonstrated hair follicle miniaturization and a lichenoid inflammatory infiltrate targeting the upper follicle region. Advanced lesions showed perifollicular lamellar fibrosis and completely fibrosed follicular tracts indistinguishable from end-stage lichen planopilaris, pseudopelade, or follicular degeneration syndrome. Some patients with androgenetic alopecia might have additional clinical and histological features of inflammation and fibrosis limited to the area of androgenetic hair loss. In these patients, the histological findings of early lesions are identical to those seen in lichen planopilaris. The lichenoid tissue reaction leading to follicular destruction in these patients might be pathogenetically related to the events underlying androgenetic alopecia.

Objectives: Lichen planus (LP) is a chronic papulosquamous disease that presents as shiny, violaceous, flat-topped, polygonal papules. Diagnosis is usually clinical, although dermatoscopy and biopsy may be needed in cases of diagnostic dilemma. As recent trends favour non-invasive modalities, the role of dermatoscopy has significantly increased. It appears to be a more convenient, safer, and quicker diagnostic modality compared to conventional histopathological examination. We aimed to study the clinical and dermatoscopic features of different variants of lichen planus and to correlate clinical and dermatoscopic features with histopathological findings. Material and Methods: The prospective observational study was conducted on patients with cutaneous LP. A total of 102 patients were included in the study after applying the inclusion and exclusion criteria. Patient particulars, clinical examination, dermatoscopic examination, and histopathological examination (HPE) were performed, and the findings were noted. Results: Female preponderance was observed (56.9% of cases) in our study, with a female-to-male ratio of 1.31:1. Classic lichen planus [59 (57.8%)] constituted most patients in our study, followed by hypertrophic lichen planus [18 (17.7%)]. On dermatoscopy of classic LP, red globules (42.4%), with patchy arrangements (35.6%), and Wickham’s striae (94.9%) were the most common findings noted. A hem-like pattern was observed in 70% of cases of lichen planus pigmentosus. Arboriform vessels was the most common vascular morphology in lichen planopilaris. Hyperkeratosis (86.4%), lichenoid infiltrate (100%), and perivascular infiltrates (78.0%) were common histopathological findings noted in classic LP. Atrophy (80.0%) was the most common finding in LP pigmentosus. Wickham's striae and grey-blue dots on dermatoscopy correlated with hypergranulosis and pigmentary incontinence on histopathology, respectively, in cases of classic LP. Wickham's striae on dermatoscopy correlated with hypergranulosis on histopathology in cases of hypertrophic LP. Perifollicular scales on dermatoscopy correlated with follicular plugging on histopathology of lichen planopilaris. Conclusion: Most variants of Lichen planus have characteristic findings on dermatoscopy. Wickham's striae can be considered a unique finding of LP, seen in almost all cases of Classic LP. Grey-blue dots on dermatoscopy correlate with pigmentary incontinence on histopathology in classic LP and lichen plano pilaris; Wickham's striae on dermatoscopy correlates more with hypergranulosis than with hyperkeratosis on histopathology in cases of classic LP and hypertrophic LP. Dermatoscopy can act as a link between clinical and histopathological findings and can obviate the need for a biopsy.