Clinical practice. Lichen planus

[Nail changes in inflammatory dermatoses: recognition and treatment]

In many cases, chronic inflammatory dermatoses are accompanied by changes of the nails or periungual region. Sometimes nail changes occur even before the onset of the particular skin disease. In some cases, specific lesions of the nails and the perionychium can contribute to the diagnosis. This review describes the most common nail and periungual changes in chronic inflammatory dermatoses and the corresponding treatment options. Among others, this review deals with nail changes in collagenoses, autoimmune bullous dermatoses, alopecia areata, lichen planus and atopic eczema. Nail psoriasis is not discussed here, as this special edition contains a review devoted entirely to the complex topic of nail psoriasis.

A Comprehensive Systematic Review of Natural Biomedicines for Immune-Mediated and Inflammatory Dermatologic Diseases

BACKGROUND

Natural biomedicines (NBMs) are frequently used to manage immune-mediated and inflammatory dermatologic diseases (IMIDDs). This systematic review evaluates the efficacy, safety, and clinical relevance of NBMs in IMIDDs, providing an evidence-based analysis to guide dermatologic practice.

METHODS

Following PRISMA guidelines, a systematic search was conducted in PubMed, Embase, Medline, and Google Scholar for randomized controlled trials (RCTs) investigating NBMs in IMIDDs from 1990 to 2023. Studies were included if they met predefined eligibility criteria: RCT design, relevant IMIDD condition, NBM intervention, and quantitative outcome measures. Risk of bias was assessed using the Jadad scale. Results were synthesized qualitatively due to heterogeneity in study designs and outcome measures.

RESULTS

Of 1364 records screened, 95 RCTs were included, encompassing 5265 participants across 23 countries. Indigo naturalis, fish oil (⍵-3), and aloe vera demonstrated the most consistent efficacy in managing psoriasis, systemic lupus erythematosus (SLE), atopic dermatitis (AD), and lichen planus (LP). Indigo naturalis significantly improved erythema, scaling, and PASI scores in psoriasis patients. Fish oil showed benefits in SLE disease activity indices and AD severity, while aloe vera demonstrated improvements in SCORAD and LP severity criteria. Most NBMs exhibited favorable safety profiles, although adverse event reporting was inconsistent.

DISCUSSION

While these findings highlight the potential of NBMs in dermatologic care, methodological limitations, including small sample sizes, heterogeneity in study designs, and lack of direct comparisons to conventional therapies, limit definitive conclusions. Additionally, not all natural agents can be easily searched and captured in systematic reviews, which may have restricted the scope of included NBMs. Future research should emphasize high-quality RCTs, standardized outcome measures, and comparative studies against conventional treatments.

TRIAL REGISTRATION

The review protocol is registered with Open Science Framework (OSF) ( https://doi.org/10.17605/OSF.IO/UH9XJ ).

Prevalence and treatment patterns of lichen planus

BACKGROUND

Lichen planus (LP) is a chronic mucocutaneous inflammatory disease with significant morbidity but data on epidemiology and therapeutics for LP is limited.

OBJECTIVE

To describe overall prevalence of LP and dermatologist-prescribed LP treatments in US adults.

METHODS

Using the Explorys database, we analyzed prevalence of overall LP and dermatologists' utilization of medications of interest.

RESULTS

Among 566,851 eligible patients in the prevalence analysis, there were 1098 LP cases with a median age of 66 years. Overall crude prevalence of LP was 0.19% (95% CI 0.18-0.21) with higher prevalence in females (prevalence ratio vs males 1.77, 95% CI 1.53-2.05). Standardized overall prevalence was 0.15%. Most LP patients diagnosed by dermatologists remained untreated after 1 year (n = 1061, 53%); the most common initial treatment was topical corticosteroids (38%). Treatment continuation after 1 year and switching were most common after initial use of systemic immunosuppressants (28% and 46%, respectively).

LIMITATIONS

The lack of a precise diagnosis code for nonoral LP allows for the potential of misclassification; disease severity cannot be established.

CONCLUSIONS AND RELEVANCE

Standardized prevalence of overall LP was 0.15%. For patients requiring systemic immunosuppressive medications, treatment continuation and switching were more common, suggesting that further research into medication selection for LP may be clinically beneficial.

Lichen Planus Initially Presenting as Poikiloderma: A Challenging Case Report

Lichen planus (LP) is a chronic inflammatory disorder that affects the skin, mucous membranes, nails, and hair. Cutaneous LP (CLP) is characterized by violaceous, polygonal, flat-topped papules and plaques that are intensely pruritic. Although it can develop on any part of the body, it most commonly affects the flexor surfaces of the wrists, lower back, and ankles. This report presents an atypical case of LP in a 33-year-old woman who initially exhibited poikilodermatous changes with bluish-gray patches, persisting for a decade. Due to the overlapping clinical and histopathological features, an extensive diagnostic workup including pan-computed tomography, lymph node biopsy, and immunohistochemistry was performed to exclude poikilodermatous mycosis fungoides. One year later, skin examination and histopathological evaluation revealed the classical features of LP, leading to a definitive diagnosis. This case highlights an unusual presentation in which poikiloderma preceded the classic clinical picture of LP. Our findings contribute to the existing knowledge of LP by emphasizing the importance of recognizing atypical presentations for accurate diagnosis and management.

History, clinical presentation, therapy, and patient reported outcomes of mucosal lichen planus: a cross-sectional study

BACKGROUND AND OBJECTIVES

Mucosal lichen planus (LP) is a chronic inflammatory disease. The patient's journey can be arduous as diagnosis and therapy are challenging.

PATIENTS AND METHODS

In this cross-sectional study, a wide range of characteristics of the patient's journey were assessed and evaluated from a total of 72 patients with mucosal LP who were treated in the dermatology departments of six German university medical centers between 02/2022 and 07/2023.

RESULTS

On average, 18.1 months elapsed between the onset of symptoms and diagnosis. Until the correct diagnosis was made, an average of 3.1 different physicians of the same or different specialties were consulted. 28.1% of patients also had cutaneous involvement. Therapeutically, 68% of patients received at least one systemic drug. Both topical (90%, 65/72) and systemic (oral, 50% of patients, 36/72; intravenous, 33%, 24/72) glucocorticoids were most frequently used. Systemic agents were most often discontinued due to ineffectiveness (46%, 50/110). Satisfaction with treatment was highest for intravenous and topical glucocorticoids (moderate to high satisfaction: 59% and 36%, respectively), and lowest for retinoids with 8%.

CONCLUSIONS

This study indicates that there might be a lack of diagnostic awareness among physicians and the unmet need for effective systemic treatment options.

Low Incidence of Oral Squamous Cell Carcinoma in Patients With Oral Lichen Planus on Sustained Anti-Inflammatory Therapy: A Single-Centre Retrospective Study of 273 Patients

BACKGROUND

Oral lichen planus (OLP), a chronic inflammatory disease, can progress to oral squamous cell carcinoma (OSCC). The malignant transformation rate may be lower in OLP patients receiving anti-inflammatory therapy.

OBJECTIVE

To describe cases of malignant transformation among OLP patients on topical/systemic anti-inflammatory therapy.

METHODS

The medical records of 273 patients with OLP at an academic institution were retrospectively reviewed. Patients with epithelial dysplasia at OLP diagnosis were excluded. Biopsy-confirmed OSCC cases diagnosed ≥6 months after the initial visit were included. Chi-square and t-tests compared categorical and numerical variables, respectively.

RESULTS

The mean age at OLP diagnosis was 63 years (standard deviation [SD]: 12.2, range: 19-92); 79.9% were women and 89.4% were White. Most patients had erosive OLP (EOLP) (61.9%). 16.5% had concurrent genital LP and 10.6% had cutaneous LP. Tacrolimus swish-and-spit was the most frequently prescribed treatment (100%), followed by 10 mg clotrimazole troches (89.4%) and topical corticosteroids (85%). The median duration of clinical follow-up was 2.9 years (interquartile range: 1-5.5). Three (1.1%) patients developed OSCC on average 6.3 years post-OLP diagnosis, all with EOLP. OSCC most frequently affected the tongue (66.7%), followed by the gingiva (33.3%). Out of 3 tumours, one was stage II, one was stage III, and one was stage IV. OLP patients with vs. without OSCC were more often male (P = .04) and more frequently experienced dysphagia (P < .001).

CONCLUSION

OSCC incidence was low in OLP patients on sustained anti-inflammatory therapy, occurring exclusively in those with EOLP. Males and patients with dysphagia more often developed OSCC.

Hypertrophic Lichen Planus and Hypertrophic Skin Lesions Associated with Histological Lichenoid Infiltrate: A Case Report and Literature Review

Hypertrophic lichen planus (HLP) is a chronic inflammatory skin condition defined by verrucous, pruritic, papules and plaques usually affecting the lower limbs. The diagnosis of HLP is primarily clinical. However, due to its feasible generalized presentation and similarities with other hypertrophic cutaneous disorders, histological evaluation is often necessary. Many dermatological conditions that present with a hypertrophic clinical appearance can arise from a histological lichenoid infiltrate (HCLI). Hence, we provide an overview of the clinical, histopathological, and prognostic features of selected HCLI, including HLP, hypertrophic lichenoid dermatitis, hypertrophic lichen sclerosus (HLS), lichen simplex chronicus (LSC), squamous cell carcinoma (SCC), keratoacanthoma (KA), pseudoepitheliomatous hyperplasia (PEH), viral warts, and lupus erythematosus/lichen planus (LE/LP) overlap. Choosing the appropriate procedure and the anatomical site for an incisional biopsy requires thoughtful consideration to ensure sufficient depth and improve diagnostic accuracy by identifying the histological features specific to each hypertrophic condition.

The role of skin microbiota in lichen planus from a Mendelian randomization perspective

Lichen planus is a chronic skin lesion characterized by pruritic violaceous papules, which has a high risk of morbidity. Skin microbiota plays an important role in the maintenance of cutaneous mucosal barrier and human health and immune homeostasis. Studies have shown that skin microbiota may play a role in the pathogenesis of lichen planus, but it is not yet clear. MR studies have been performed to determine causal associations. Lichen planus samples from Finn database were extracted from published GWAS data, including 6,411 cases and 405,770 controls; skin microbiota samples were gathered from a meta-analysis of German population-based GWAS, which included 1,656 skin samples from two cohorts: KORA FF4 (n = 353) and PopGen (n = 294), comprising 4,685,714 SNPs. The IVW method was used as the main statistical method, supplemented by three methods: MR-Egger, weighted median and weighted mode. FDR correction and MR Steiger test were used to reduce false positives. IVW method revealed a negative correlation between Burkholderia in the moist anterior elbow and lichen planus (OR: 0.934, 95% CI: 0.910-0.986, P = 0.017). These associations remained stable following false discovery rate correction (P < 1e-5). Our study highlights a possible causal role of Burkholderia in the development of lichen planus and suggests that Burkholderia may reduce the occurrence of lichen planus by affecting macrophages.

New-onset cutaneous lichen planus following Vaxzevria (Oxford-AstraZeneca) COVID-19 vaccination

We report a 56-year-old male who developed cutaneous lichen planus (LP) following Vaxzevria (Oxford-AstraZeneca) COVID-19 vaccination. Multiple topical and systemic therapies were tried with limited success; however, partial improvement was observed with narrow-band UVB (NB-UVB) phototherapy. This report adds to the growing evidence of new-onset LP following COVID-19 vaccination and underscores the need for careful reporting, monitoring, and management of vaccine-related adverse effects.

Picolinate-mediated immunomodulation: insights from Mendelian randomization on the role of NK cell percentage in the pathogenesis of lichen planus

Background

Lichen planus (LP), an autoimmune disorder, remains incompletely understood in terms of its etiological mechanisms. This study aims to elucidate causal relationships among immune cell populations, plasma metabolites, and lichen planus using Mendelian randomization (MR) techniques.

Methods

Employing a two-sample, two-step MR approach, with single nucleotide polymorphisms (SNP) serving as genetic instruments for both exposures and mediators, this study minimizes biases from confounding and reverse causality. Leveraging summary statistics from genome-wide association studies (GWAS) involving 731 immune cell traits (N = 3757), 1091 plasma metabolite traits (N = 8299), and lichen planus (N = 367668), inverse variance weighting (IVW) is adopted as the primary MR analytical method. The total effect of immune cells traits on LP is decomposed into direct and indirect effects mediated by plasma metabolites.

Results

MR analysis reveals causal associations for 28 immune cell traits and 38 plasma metabolites with LP (PIVW < 0.05). Specifically, NK % lymphocyte shows a negatively correlated causal effect with LP (ORIVW = 0.952; 95% CI: [0.910, 0.995], PIVW = 0.030). Among mediators, Picolinate significantly contributes, explaining 16.4% (95% CI: [28.3%, 4.54%]) of the association between NK % lymphocyte and LP.

Conclusion

These findings support a potential protective causal effect of NK % lymphocyte on LP, partially mediated by Picolinate levels. Thus, interventions targeting Picolinate levels may mitigate LP burden attributed to low NK % lymphocyte counts. This study provides new evidence and insights into the pathogenesis of lichen planus, advancing our understanding of its underlying mechanisms.

Retrospective Analysis of Blood Inflammatory Biomarkers in Patients with Oral Lichen Planus: Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio

Objectives: Oral lichen planus (OLP) is a potentially malignant disorder and a chronic inflammatory condition of an immune nature. The aim of this study was to investigate the association between immune-inflammatory biomarkers in patients with OLP and a control group. Materials and Methods: This was a retrospective study with 129 patients (62 with OLP and 67 controls) in which clinical and laboratory data were analyzed. The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), the mean platelet volume (MPV) index, and the parameter of systemic immune-inflammation index (SII) were assessed. Results: In patients with OLP, the average time of progression was significantly longer when the condition manifested in the atrophic-erosive form (4.3 ± 3.2 years) as opposed to the reticular form (1.8 ± 0.9 years) (p = 0.018). With regard to NLR, no differences were found in terms of age (p = 0.346 (r = 0.08)), tobacco use (p = 0.807), sex (p = 0.088), alcohol consumption (p = 0.281), clinical form of OLP (p = 0.55), time of progression of OLP (p = 0.309 (r = -0.13)), and number of sites (p = 0.217). The same was observed for the systemic immune-inflammation index. Conclusion: The lack of significant statistical associations between the biomarkers and parameters (NLR, PLR, MPV, and SII index) in patients with oral lichen planus makes such parameters of very limited use in clinical OLP practice.

Esophageal Lichen Planus: The Efficacy and Safety of Tacrolimus in Reducing Inflammation and Need for Dilation

INTRODUCTION

Esophageal lichen planus (ELP) is a rare inflammatory disease most seen in middle-aged White women, manifested by sloughing mucosa, thick exudate, and proximal strictures. Most case reports and small series highlight using steroids and other immunosuppressants. To the best of our knowledge, oral tablet tacrolimus has not been studied. We aimed to assess the change in ELP after oral tacrolimus treatment.

METHODS

The primary outcome was the efficacy of tacrolimus objectively through our scoring system, ELP Severity Score (ELPSS). All consecutive adults with ELP who underwent more than one esophagogastroduodenoscopy by 2 esophagologists and being treated with tacrolimus or other treatment were eligible for inclusion in this retrospective cohort study. Inflammation and fibrostenotic disease were graded using the novel ELPSS.

RESULTS

Twenty-two patients met the inclusion criteria. Half (11) received tacrolimus (dose 1-2 mg twice daily), and half (11) received other therapy (i.e., cyclosporine, topical steroids, or none). Mean ELPSS on the first esophagogastroduodenoscopy, extraesophageal manifestations of disease, presenting symptoms, and baseline characteristics were similar between groups. Among patients on Tac vs No-Tac, there was a statistically significant improvement in ELPSS (mean difference 1.8 pts; 95% confidence interval 0.25-3.38; P = 0.02). Response rate was 89% with Tac vs 30% with No-Tac ( P = 0.025). All 22 patients underwent bougie dilation safely with a mean diameter of 16 mm achieved. Patients on Tac also required less frequent dilation.

DISCUSSION

Oral tablet tacrolimus reduced the inflammatory and fibrostenotic components of ELP. Thus, low-dose oral tacrolimus is safe and should be considered in patients with more severe disease.

Widespread purplish-red plaques with plasma cell infiltrate: A rare type of lichen planus

Diseases in which cutaneous plasma cell infiltrates predominate are rare and usually of unknown etiology, including those that transition from benign to malignant, such as cutaneous plasmacytosis, multicentric Castleman disease, and extramedullary plasmacytoma. These diseases may present as purplish, reddish-brown cutaneous plaques or nodules. Here, we report an exceptional case of lichen planus (LP) in which the patient had classic histopathological features, but the infiltrating inflammatory cells were plasma cells with restricted light chain expression. The patient presented with severe rashes, including purplish-red plaques and nodules, erythema, and erosions in the palmoplantar area, verrucous hyperplasia of the oral mucosa, and anonychia of the toes. These findings suggest a possible role of plasma cells with restricted light chain expression in the LP. Clinicians should closely follow patients for changes in their rash, perform repeat biopsies if necessary, and regularly conduct multisystemic evaluations.

Correlations between lichen planus and autoimmune diseases: a Mendelian randomization study

Previous observational studies have found that lichen planus (LP) is associated with autoimmune diseases. To determine the association between LP and 15 autoimmune diseases, we applied the Mendelian randomization (MR) approach, which uses genetic variants as a tool to improve causal inference. We performed a two-sample MR with the genetic instruments identified for 15 autoimmune diseases. Genome-wide association study (GWAS) data was sourced from the IEU Open GWAS database. The instrumental variables (IVs) for LP (1865 cases and 212,242 non-cases) were genetic variations highly associated (P < 5 × 10-6) with LP in the European population. To calculate causal effects, odds ratios (ORs) with 95% confidence intervals (CIs) are employed. MR showed that the genetic risk of psoriasis was positively associated with atopic dermatitis (OR [95%CI] = 0.964[0.936, 0.992], PIVW = 0.013), ankylosing spondylitis (OR [95%CI] = 0.879[0.774, 0.999], PIVW = 0.047) and Type 1 diabetes (OR [95%CI] = 1.074[1.008, 1.145], PIVW = 0.027). These results didn't exhibit horizontal pleiotropy, and "leave-one-out" analysis demonstrated result stability. The MR study indicates a causal relationship between atopic dermatitis, ankylosing spondylitis and Type 1 diabetes in Europe. Further research is necessary to clarify the biological mechanisms that underlie these associations.

Secukinumab in adult patients with lichen planus: efficacy and safety results from the randomized placebo-controlled proof-of-concept PRELUDE study

BACKGROUND

Patients with lichen planus (LP) refractory to available therapies often experience a high disease burden, representing a population with a clear unmet need for new treatments.

OBJECTIVES

To evaluate the efficacy and safety of secukinumab 300 mg over 32 weeks in adult patients with biopsy-proven cutaneous LP (CLP), mucosal LP (MLP) or lichen planopilaris (LPP) that is inadequately controlled by topical corticosteroids.

METHODS

PRELUDE was a randomized double-blind placebo-controlled phase II proof-of-concept study that enrolled patients with CLP, MLP or LPP. Eligible patients were randomized to either secukinumab 300 mg every 4 weeks for 32 weeks (SECQ4W) or placebo for 16 weeks followed by secukinumab 300 mg every 2 weeks (SECQ2W) for 16 weeks. The primary endpoint was achievement of the newly designed Investigator's Global Assessment (IGA) score ≤ 2 at week 16.

RESULTS

Overall, 111 patients were randomized (n = 37 each) to CLP, MLP and LPP cohorts. As the proof-of-concept criteria were not met for any of the three cohorts, the primary objective was not met. A numerically higher proportion of patients achieved IGA ≤ 2 response at week 16 with SECQ4W vs. placebo in the MLP {37.5% [95% credibility interval (Crl) 20.3-57.2] vs. 23.1% (95% Crl 6.5-49.2)} and LPP cohorts [37.5% (95% Crl 20.2-57.3) vs. 30.8% (95% Crl 10.8-57.6)]. In the LPP cohort, a sustained response for IGA ≤ 2 from week 16 to week 32 was achieved with SECQ4W (week 16, 37.5%; week 32, 45.8%), and a substantial improvement was observed in IGA ≤ 2 response in patients from this cohort who switched from placebo (week 16, 30.8%) to SECQ2W after week 16 (week 32, 63.6%). The safety profile was consistent with the known profile of secukinumab and showed no new or unexpected signals.

CONCLUSIONS

PRELUDE is the first randomized controlled basket trial evaluating interleukin (IL)-17A inhibition with secukinumab across three subtypes of LP. Secukinumab was well tolerated and safe, showing different response rates across the three subtypes, with numerical IGA improvements in MLP and LPP, and no response in CLP. The study raises the question of a differential role of IL-17A across LP subtypes. The novel IGA score showed significant correlation with both patient- and physician-reported outcome measurements.

Erosive lichen planus: an unmet disease burden

Objectives

To explore the demographic and clinical profile of erosive lichen planus (ELP) across multiple ethnicities within a single cohort, deepening our understanding of disease severity, progression and outcomes.

Methods

A longitudinal retrospective cohort study of ELP patients in the ethnically diverse population of East London was carried out, profiling ELP (n = 57) against the milder reticular lichen planus (RLP) (n = 35).

Results

A higher prevalence of ELP was observed in white populations compared to other ethnicities. Affected females were no more likely than males to develop ELP. There was an increased time to diagnosis for ELP patients (median ELP: 452 days, RLP: 312 days), spending longer in primary care before onward referral, in particular when referred by their general medical practitioner (GP) (median dentist 313 days, GP: 606 days). Depression was more likely to occur alongside ELP. Being an ex-smoker is a risk factor for ELP while being a current smoker is associated with RLP. A higher proportion of patients with ELP were missing teeth and had periodontal disease. Multisite involvement was more common in ELP, (ELP: 68% RLP: 11.43%). 55% of ELP cases developed scarring and were less likely to respond to first line medications, requiring systemic immunosuppression. The duration of follow up was increased in the ELP who were reviewed for almost twice as long as RLP patients (ELP 71 months, RLP 35 months).

Conclusion

ELP takes longer to diagnose, requires prolonged tertiary care and is more resistant to treatment, when compared across multiple ethnicities. These patients have increased medical and oral health needs and are at greater risk of scarring than the reticular form. A greater education amongst primary carers on its presentation, as well as a greater understanding of the cellular and molecular mechanisms driving ELP are required to improve diagnostics and identify novel therapeutic approaches.

Distinct Variations in Gene Expression and Cell Composition across Lichen Planus Subtypes

Lichen planus (LP) is a highly prevalent inflammatory skin disease. While various clinical subtypes have been defined, detailed comparisons of these variants are lacking. This study aimed to elucidate differences in gene expression and cellular composition across LP subtypes. Lesional skin biopsies from 28 LP patients (classical, oral, genital, and lichen planopilaris) and seven non-diseased skin controls (NDC) were analyzed. Gene expression profiling of 730 inflammation-related genes was conducted using NanoString. Immune cell compositions were assessed by multiplex immunohistochemistry. Gene expression profiles revealed unique inflammatory signatures for each LP subtype. Lichen planopilaris exhibited the most divergence, with downregulated gene expression and upregulation of complement pathway genes (C5-7), along with elevated M2 macrophages. Oral and genital LP demonstrated similar profiles with strong upregulation of TNF-related and Toll-like receptor-associated genes. Oral LP showed the highest upregulation of cytotoxicity-associated genes, as well as high numbers of CD8+ IL-17A+ (Tc17) cells (8.02%). Interferon gene signatures were strongly upregulated in oral and classical LP. The study highlights distinct differences in inflammatory gene expression and cell composition across LP subtypes, emphasizing the need for tailored therapeutic approaches.

Intra-lesional Corticosteroids Versus Platelet-Rich Plasma Versus Platelet-Rich Fibrin for the Treatment of Oral Lichen Planus: A Systematic Review and Network Meta-Analysis

Oral lichen planus (OLP) is a potentially malignant disorder affecting the oral mucosa. Platelet concentrates, including platelet-rich plasma (PRP) and platelet-rich fibrin (PRF), have emerged as promising alternative treatments to corticosteroids. This study aims to comprehensively evaluate the effectiveness of PRP and PRF in the management of patients with OLP. We conducted a comprehensive search of PubMed, Scopus, Web of Science, and the Cochrane Library for randomized controlled trials (RCTs) involving patients with OLP comparing intralesional PRP or PRF with corticosteroids up to August 2024. The primary outcomes assessed were changes in lesion size, pain scores, and Thongprasom scores. Network meta-analysis (NMA) was used. Data were pooled using summary effect sizes with corresponding 95% confidence intervals (CIs) in a random-effects model based on the DerSimonian-Laird method. Eight studies comprising 157 patients and 250 lesions were included in the final analysis. Compared to corticosteroids, no significant differences were observed among PRF and PRP in terms of changes in lesion size, pain scores, clinical severity scores, and adverse events. NMA ranking showed that PRF was the best-ranking treatment in reducing lesion sizes (SUCRA values: 72.6%, 75.8%, 66.2%, 80.8%, and 77.5% at first, second, third, fourth, and eighth weeks of assessment), followed by corticosteroids, and PRP. Moreover, PRF was the best-ranking treatment in reducing pain score at the first, third, and eighth weeks of assessment (SUCRA values: 91.8%, 86%, and 85.9%), while PRP was the best intervention at the second and fourth weeks of assessment (SUCRA values: 61.3%, and 90.2%). Also, PRF was the best intervention in terms of Thongprasom scores at eight weeks of assessment (SUCRA value: 77.3%), while PRP was the best intervention at the fourth week of assessment with value of 78.1%. PRF and PRP showed comparable results with intralesional corticosteroids in all studied parameters. Considering treatments ranking, PRF was the best intervention. The optimal treatment modality for OLP varies on different clinical conditions.

Remission of refractory esophageal lichen planus induced by tofacitinib

As of now, there exists no established therapy for ELP. Retinoids, which are standard in treating cutaneous LP, do not exhibit positive effects in ELP. While topical glucocorticosteroids often yield favorable responses in esophageal inflammation, some cases prove recalcitrant or refractory. In such instances, various immunosuppressive therapies have been attempted with variable success.This report details a severe case of ELP that showed resistance to prednisolone, acitretin, alitretinoin, adalimumab, tacrolimus, hydroxychloroquine plus mycophenolate mofetil, and cyclophosphamide. The initiation of the JAK inhibitor tofacitinib induced an impressive clinical, endoscopic, and histological remission. This positive response to a JAK inhibitor is discussed in the context of our evolving understanding of the immune-mediated pathogenesis of this disease.

Cheilitis: A Diagnostic Algorithm and Review of Underlying Etiologies

Cheilitis, or inflammation of the lips, is a common reason for dermatologic consultation. The inflammation can include the vermillion lip, vermillion border, and surrounding skin, and can present with an acute or chronic course. There are many etiologies, including irritant and allergic contact dermatitis, atopic cheilitis, actinic cheilitis, infectious etiologies, nutritional deficiencies, drug-induced cheilitis, and rare etiologies, including granulomatous cheilitis, cheilitis glandularis, plasma cell cheilitis, lupus cheilitis, and exfoliative cheilitis. Distinguishing among the various etiologies of cheilitis is clinically difficult, as many causes may produce similar erythema and superficial desquamation of mucosal skin. In addition, patients report dryness, redness, irritation, burning, fissuring, and itch in many of the underlying causes. Thus, the specific etiology of cheilitis is often difficult to diagnose, requiring extensive testing and treatment trials. In this review, we summarize the various types of cheilitis, synthesizing novel cases, clinical presentations, histopathology, epidemiology, and advancements in diagnostic methods and therapeutics. We provide a diagnostic algorithm aimed to assist clinicians in the management of cheilitis.

Role of Vitamin D in Oral Lichen Planus: A Case Control Study

BACKGROUND

It has been reported that vitamin D deficiency may be associated with the development of oral lichen planus (OLP). Given the high prevalence of vitamin D deficiency in many countries, we sought to determine whether it constitutes a comorbidity of OLP.

METHODS

One hundred and twenty patients clinically and histologically diagnosed with OLP were evaluated for their serum vitamin D levels. The results were compared to results from a control series of the same number of subjects matched for age and sex.

RESULTS

Vitamin D deficiency was diagnosed in 45% (n = 54) of OLP patients and in 26.7% (n = 32) of the control group. Vitamin D supplements were being taken by 32 (26.7%) OLP patients and 15 (12.5%) subjects in the control group. A multivariate logistic regression model showed that OLP was associated with vitamin D deficiency [OR: 2.24 (1.28-3.98, p = 0.005)] and vitamin D supplementation [OR: 2.51 (1.25-5.22, p = 0.011)], even after controlling for confounding variables such as sex, age ≤60>, tobacco, and alcohol.

CONCLUSION

The association between OLP patients and vitamin D deficiency or vitamin D supplementation suggests that further research might explore the benefits of vitamin D supplements in managing OLP patients.

Could Vaccination against COVID-19 Trigger Immune-Mediated Inflammatory Diseases?

Exacerbations and new onset of immune-mediated inflammatory diseases, such as psoriasis and hidradenitis suppurativa, have been reported following COVID-19 vaccination. In patients with hidradenitis suppurativa, recent studies have shown that those who received mRNA vaccines were 3.5 times as likely to develop flares following vaccination compared to patients who received non-mRNA vaccines, indicating that mRNA COVID-19 vaccines are associated with hidradenitis suppurativa flares. Similar findings have been found in other studies evaluating the association between COVID-19 vaccines and other immune-mediated inflammatory diseases such as psoriasis, atopic dermatitis, lichen planus, and alopecia areata. However, further research is warranted in larger populations to validate these findings.

Budesonide Orodispersible Tablet for the Treatment of Refractory Esophageal Lichen Planus

Esophageal lichen planus is an uncommon but highly morbid condition where effective treatments are limited. Diagnosis may be challenging and requires a high degree of clinical suspicion considering endoscopic, histopathological, esophageal, and extraesophageal manifestations. We describe a severe case of esophageal lichen planus and recurrent esophageal stricture that was refractory to acid suppression, local and systemic steroid formulations, and dilatation. We present the first reported use of budesonide orodispersible tablet for this condition, including the excellent clinical, endoscopic, and histopathological response.

Oral and non-oral lichen planus show genetic heterogeneity and differential risk for autoimmune disease and oral cancer

Lichen planus (LP) is a T-cell-mediated inflammatory disease affecting squamous epithelia in many parts of the body, most often the skin and oral mucosa. Cutaneous LP is usually transient and oral LP (OLP) is most often chronic, so we performed a large-scale genetic and epidemiological study of LP to address whether the oral and non-oral subgroups have shared or distinct underlying pathologies and their overlap with autoimmune disease. Using lifelong records covering diagnoses, procedures, and clinic identity from 473,580 individuals in the FinnGen study, genome-wide association analyses were conducted on carefully constructed subcategories of OLP (n = 3,323) and non-oral LP (n = 4,356) and on the combined group. We identified 15 genome-wide significant associations in FinnGen and an additional 12 when meta-analyzed with UKBB (27 independent associations at 25 distinct genomic locations), most of which are shared between oral and non-oral LP. Many associations coincide with known autoimmune disease loci, consistent with the epidemiologic enrichment of LP with hypothyroidism and other autoimmune diseases. Notably, a third of the FinnGen associations demonstrate significant differences between OLP and non-OLP. We also observed a 13.6-fold risk for tongue cancer and an elevated risk for other oral cancers in OLP, in agreement with earlier reports that connect LP with higher cancer incidence. In addition to a large-scale dissection of LP genetics and comorbidities, our study demonstrates the use of comprehensive, multidimensional health registry data to address outstanding clinical questions and reveal underlying biological mechanisms in common but understudied diseases.

Hypertrophic Lichen Planus: An Up-to-Date Review and Differential Diagnosis

CONTEXT.—

Hypertrophic lichen planus (HLP) is a variant of lichen planus that can be difficult to diagnose based on histopathologic features alone. Thus, patient clinical history and clinicopathologic correlation are essential considerations to make the correct diagnosis.

OBJECTIVE.—

To discuss the clinical and histologic presentation of HLP and provide a thorough review of commonly encountered mimickers in the differential diagnosis.

DATA SOURCES.—

Data were derived from a literature review, personal clinical and research experiences, and a review of cases in the archives of a tertiary care referral center.

CONCLUSIONS.—

In general, HLP involves the lower extremities and is characterized by thickened, scaly nodules and plaques that are often pruritic and chronic in nature. HLP affects both males and females and is most common in adults 50 to 75 years of age. Unlike conventional lichen planus, HLP tends to have eosinophils and classically displays a lymphocytic infiltrate most concentrated around the tips of rete ridges. The differential diagnosis for HLP is broad and encompasses numerous entities in many different categories, including premalignant and malignant neoplasms, reactive squamoproliferative tumors, benign epidermal neoplasms, connective tissue disease, autoimmune bullous disease, infection, and drug-related reactions. Therefore, a high index of suspicion must be maintained to avoid a misdiagnosis and potential inappropriate treatments.

Case report: Hypertrophic lichen planus initially misdiagnosed as squamous cell carcinoma

Fewer than 26 case reports describe hypertrophic lichen planus (HLP) misdiagnosed as cutaneous squamous cell carcinoma (cSCC). It can be difficult to distinguish between HLP and cSCC, as these two conditions share many clinical and histopathological characteristics. Patients who are misdiagnosed with cSCC often undergo unnecessary medical and/or surgical interventions before receiving a diagnosis of HLP and improving on HLP-directed therapy. This case series highlights the course of three female patients, referred to a single tertiary institution between 2018 and 2022, who were initially misdiagnosed with cSCC before receiving a diagnosis of HLP. We have emphasized the clinical and histopathological distinguishing features between HLP and cSCC, the pathogenesis of HLP, and current and new HLP-directed therapy. We hope that this case series serves as a reminder to dermatologists, dermatologic surgeons, and dermatopathologists to be aware of this diagnostic challenge.

Esophageal Lichen Planus: A Descriptive Multicenter Report

GOALS

To better understand the characteristics, treatment approaches, and outcomes of patients with esophageal lichen planus (ELP).

BACKGROUND

ELP is a rare, often unrecognized and misdiagnosed disorder. Data on this unique patient population are currently limited to small, single-center series.

STUDY

A multicenter, retrospective descriptive study was conducted of adults diagnosed with ELP over a 5-year period, between January 1, 2015, and October 10, 2020, from 7 centers across the United States.

RESULTS

Seventy-eight patients (average age 65 y, 86% female, 90% Caucasian) were included. Over half had at least 1 extraesophageal manifestation. Esophageal strictures (54%) and abnormal mucosa (50%) were frequent endoscopic findings, with the proximal esophagus the most common site of stricture. Approximately 20% had normal endoscopic findings. Topical steroids (64%) and/or proton pump inhibitors (74%) dominated management; endoscopic response favored steroids (43% vs. 29% respectively). Almost half of the patients required switching treatment modalities during the study period. Adjunctive therapies varied significantly between centers.

CONCLUSIONS

Given its at times subtle clinical and endoscopic signs, a high index of suspicion and biopsy will improve ELP diagnosis, especially in those with extraesophageal manifestations. Effective therapies are lacking and vary significantly. Prospective investigations into optimal treatment regimens are necessary.

Efficient diagnosis of psoriasis and lichen planus cutaneous diseases using deep learning approach

The tendency of skin diseases to manifest in a unique and yet similar appearance, absence of enough competent dermatologists, and urgency of diagnosis and classification on time and accurately, makes the need of machine aided diagnosis blatant. This study is conducted with the purpose of broadening the research in skin disease diagnosis with computer by traversing the capabilities of deep Learning algorithms to classify two skin diseases noticeably close in appearance, Psoriasis and Lichen Planus. The resemblance between these two skin diseases is striking, often resulting in their classification within the same category. Despite this, there is a dearth of research focusing specifically on these diseases. A customized 50 layers ResNet-50 architecture of convolutional neural network is used and the results are validated through fivefold cross-validation, threefold cross-validation, and random split. By utilizing advanced data augmentation and class balancing techniques, the diversity of the dataset has increased, and the dataset imbalance has been minimized. ResNet-50 has achieved an accuracy of 89.07%, sensitivity of 86.46%, and specificity of 86.02%. With their promising results, these algorithms make the potential of machine aided diagnosis clear. Deep Learning algorithms could provide assistance to physicians and dermatologists by classification of skin diseases, with similar appearance, in real-time.

Ultrasound Features of Nail Lichen Planus

OBJECTIVES

To describe the ultrasonographic features of nail lichen planus (NLP), which, so far, have not been reported in the literature.

METHODS

A retrospective single-center study of NLP patients' color Doppler ultrasound examinations was performed between March 2014 and January 2023. Inclusion criteria were patients ≥15 years with a confirmed clinical diagnosis of NLP in sequential order. Exclusion criteria included concomitant systemic or local cutaneous or nail diseases and systemic or local nail treatments before the ultrasound examination. The ultrasound protocol included the examination of all fingernails or toenails following the reported protocol for dermatologic ultrasound examinations at high and ultra-high frequencies. Patient demographics and ultrasound features of the nail bed, periungual region, nail plate, and regional vascularity were registered and analyzed statistically.

RESULTS

A total of 36 patients met the criteria. All cases presented thickened and decreased echogenicity of the nail bed. A hypoechoic halo surrounding the origin of the nail plate was present in 78% of cases. Exactly 58% of patients presented decreased echogenicity of the proximal periungual dermis, and 86% showed thickening of the periungual dermis. Hypervascularity of the nail bed was seen in 94% of cases. The mean maximum thickness of vessels, the peak systolic velocity of the arterial vessels, and other blood flow findings are provided.

CONCLUSION

Ultrasonography can support the diagnosis of NLP, which benefits the non-invasive discrimination of nail conditions and can avoid the potential permanent scars derived from nail biopsies. Furthermore, ultrasound may be a powerful tool to monitor this disease's treatment.

Post-radiation lichen planus: a case report and review of the literature

BACKGROUND

Lichen planus is a T-cell mediated inflammatory disorder of the skin and mucus membranes and is a rare complication of external beam radiation.

CASE PRESENTATION

64 year old White male who presented to dermatology with a lesion at the lateral aspect of the right thigh. The lesion was first noted 40 years prior and had grown from 1.5 cm to 6.5 cm in the ensuing years. On examination the lesion was raised, hypopigmented, with pearly borders and central ulceration. Wide excision with lymph node dissection demonstrated invasive squamous cell carcinoma, basaloid type, with negative margins. Patient had radiation therapy of the right inguinal nodes. Patient subsequently noted a "blister" on the right upper thigh, which progressed over time to flat, polygonal, intensely pruritic lesions that covered the right lateral thigh from just distal to the hip to the distal third of the femur (Figs. 1, 2). Skin biopsy was positive for lichen planus. He was started on topical triamcinolone with salutary effects on appearance and pruritus. Fig. 1 Lichen planus, right thigh Fig. 2 Closeup, lichen planus, right thigh, demonstrating polygonal papules CONCLUSION: Once more biopsy-proven cases of post-radiation lichen planus are reported, hopefully the exact mechanism can be elucidated. This may identify risk factors and aid in treatment, with the goal of limiting radiation toxicity and palliation of symptoms that may affect the quality of daily life.

TAZ acting as a potential pathogenic biomarker to promote the development of lichen planus

BACKGROUND

Lichen planus is a chronic inflammatory disorder. Transcriptional coactivator with PDZ-binding motif (TAZ/WWTR1) is an important downstream effector of the Hippo pathway which regulates organ size and tissue homeostasis. But little is known about the role of TAZ in lichen planus so far.

OBJECTIVE

To explore the expression of TAZ in lichen planus and normal skin, and to discover the relationship between TAZ expression and the clinical characteristics of lichen planus patients.

METHODS

The method of immunohistochemistry was performed to quantify the expression of TAZ in 262 patients with lichen planus and 90 control tissues. Western blot and quantitative real-time reverse transcriptase-PCR (qRT-PCR) analysis were performed to examine and compare TAZ expression in 4 cases of fresh lichen planus lesions and normal skin tissues.

RESULTS

TAZ was weakly expressed in the basal layers of the epidermis in normal skin tissues with a positive rate of 52.22% (47/90). But in lichen planus, TAZ was strongly expressed in almost the entire epidermis with a positive rate of 81.30% (213/262), and the difference between the two groups was statistically significant (p<0.05). Additionally, TAZ expression was significantly related to the location of the lichen planus, clinical phenotype, smoking, and alcohol preference (p<0.05). Western blot and qRT-PCR showed that the expression of TAZ in protein and mRNA levels in four cases of lichen planus lesions was significantly higher than that in normal skin tissues.

CONCLUSION

TAZ may play a regulatory role in the occurrence and development of lichen planus, which might provide a new perspective for studying pathogenesis and theoretical treatment targets.

Chromoblastomycosis Caused by Fonsecaea monophora Mimicking Lichen Planus

Chromoblastomycosis is a rare fungal infection acquired by traumatic inoculation of pigmented fungi from an environmental source. The polymorphic presentation of chromoblastomycosis may mimic other dermatologic conditions, leading to delays in diagnosis. Thus, histopathology is critical in identifying the presence of fungi and confirming the diagnosis. We present a case of chromoblastomycosis caused by the organism Fonsecaea monophora mimicking a lesion of lichen planus to highlight the importance of histopathology in the diagnosis of this condition.

Noval advance of histone modification in inflammatory skin diseases and related treatment methods

Inflammatory skin diseases are a group of diseases caused by the disruption of skin tissue due to immune system disorders. Histone modification plays a pivotal role in the pathogenesis and treatment of chronic inflammatory skin diseases, encompassing a wide range of conditions, including psoriasis, atopic dermatitis, lupus, systemic sclerosis, contact dermatitis, lichen planus, and alopecia areata. Analyzing histone modification as a significant epigenetic regulatory approach holds great promise for advancing our understanding and managing these complex disorders. Additionally, therapeutic interventions targeting histone modifications have emerged as promising strategies for effectively managing inflammatory skin disorders. This comprehensive review provides an overview of the diverse types of histone modification. We discuss the intricate association between histone modification and prevalent chronic inflammatory skin diseases. We also review current and potential therapeutic approaches that revolve around modulating histone modifications. Finally, we investigated the prospects of research on histone modifications in the context of chronic inflammatory skin diseases, paving the way for innovative therapeutic interventions and improved patient outcomes.

Syringotropic Lichen Planus: An Unusual Presentation of a Common Dermatosis - A Report of 2 Cases

Introduction

Lichen planus (LP) is a chronic inflammatory dermatosis that causes plaques and itchy papules on the skin, as well as erosion and ulcers in the mucous membranes. LP is characterized by a dense dermal T-cell infiltration. Perieccrine inflammation can be seen in a variety of dermatoses, but genuine lymphocyte permeation of the secretory coil or lymphocytic syringotropism is a rare sign that is typically seen in mycosis fungoides.

Case Presentation

In this study, we present 2 uncommon instances of lymphocytic syringotropism in LP. Histopathological examination revealed dense T-cell infiltration and lymphocytic involvement of eccrine glands, confirming syringotropism.

Conclusion

Lymphocytic syringotropism is an uncommon finding in LP. Its presence broadens the histopathological spectrum of LP and highlights the need to differentiate it from lymphoproliferative disorders like mycosis fungoides.

Crossroads between Skin and Endocrine Glands: The Interplay of Lichen Planus with Thyroid Anomalies

In this narrative review, we aimed to overview the interplay between lichen planus (LP) and thyroid conditions (TCs) from a dual perspective (dermatologic and endocrine), since a current gap in understanding LP-TC connections is found so far and the topic is still a matter of debate. We searched PubMed from Inception to October 2023 by using the key terms "lichen planus" and "thyroid", (alternatively, "endocrine" or "hormone"). We included original clinical studies in humans according to three sections: LP and TC in terms of dysfunction, autoimmunity, and neoplasia. Six studies confirmed an association between the thyroid dysfunction (exclusively hypothyroidism) and LP/OL (oral LP); of note, only one study addressed cutaneous LP. The sample size of LP/OLP groups varied from 12-14 to 1500 individuals. Hypothyroidism prevalence in OLP was of 30-50%. A higher rate of levothyroxine replacement was identified among OLP patients, at 10% versus 2.5% in controls. The highest OR (odd ratio) of treated hypothyroidism amid OLP was of 2.99 (p < 0.005). Hypothyroidism was confirmed to be associated with a milder OLP phenotype in two studies. A single cohort revealed a similar prevalence of hypothyroidism in LP versus non-LP. Non-confirmatory studies (only on OLP, not cutaneous LP) included five cohorts: a similar prevalence of hypothyroidism among OLP versus controls, and a single cohort showed that the subjects with OLP actually had a lower prevalence of hypothyroidism versus controls (1% versus 4%). Positive autoimmunity in LP/OLP was confirmed in eight studies; the size of the cohorts varied, for instance, with 619 persons with LP and with 76, 92, 105, 108, 192, 247, and 585 patients (a total of 1405) with OLP, respectively; notably, the largest control group was of 10,441 individuals. Four clusters of approaches with respect to the autoimmunity in LP/OLP were found: an analysis of HT/ATD (Hashimoto's thyroiditis/autoimmune thyroid diseases) prevalence; considerations over the specific antibody levels; sex-related features since females are more prone to autoimmunity; and associations (if any) with the clinical aspects of LP/OLP. HT prevalence in OLP versus controls was statistically significantly higher, as follows: 19% versus 5%; 12% versus 6%; and 20% versus 9.8%. A single study addressing LP found a 12% rate of ATDs. One study did not confirm a correlation between OLP-associated clinical elements (and OLP severity) and antibody values against the thyroid, and another showed that positive TPOAb (anti-thyroperoxidase antibodies) was more often found in erosive than non-erosive OLP (68% versus 33%). Just the reverse, one cohort found that OLP subjects had a statistically significantly lower rate of positive TPOAb versus controls (9% versus 15%). Five case-control studies addressed the issue of levothyroxine replacement for prior hypothyroidism in patients that were diagnosed with OLP (no study on LP was identified); three of them confirmed a higher rate of this treatment in OLP (at 8.9%, 9.7%, and 10.6%) versus controls. In conclusion, with regard to LP/OLP-TC, we note several main aspects as practical points for multidisciplinary practitioners: OLP rather than LP requires thyroid awareness; when it comes to the type of thyroid dysfunction, mostly, hypothyroidism should be expected; female patients are more prone to be associated with ATDs; a potential higher ratio of OLP subjects taking levothyroxine was found, thus a good collaboration with an endocrinology team is mandatory; and so far, OLP individuals have not been confirmed to be associated with a higher risk of thyroid nodules/cancer.

Bridging the gaps: management of lichen planus subtypes in a joint dermatology-oral surgery clinic

Lichen planus (LP) presents with a range of clinical subtypes. It can affect the outer skin, involve the nails and present with alopecia and mucosal symptoms to varying degrees. LP of the outer skin mostly shows a self-limiting course; however, this is not the case for lichen planopilaris and the mucosa-affecting subtypes. The pathogenesis of LP is still incompletely understood. As a result, an effective, targeted therapy is currently lacking and different immunomodulatory approaches are being used in clinical practice. The management of patients with severe oral LP mucosae can be particularly challenging. Although the true risk remains controversial, oral LP is considered a risk factor for the development of squamous cell carcinoma and there is a need for regular screening. The quality of life in patients with LP is significantly impaired because of frequent clinical visits, pain, soreness, inability to eat certain foods, side effects to medication, frustrating therapy attempts and worry regarding cancer risk. We highlight here the advantages of an interdisciplinary dermatology and oral surgery clinic, which can address the domains of tooth status, nutrition, pain and malignant transformation and optimized patient management.

Evaluating the Appropriateness of Existing Health-Related Quality of Life Measures in Lichen Planus

INTRODUCTION

Lichen planus (LP) is an inflammatory skin disorder that can present in various forms across the body, including lesions on the skin (cutaneous LP [CLP]), scalp (lichen planopilaris [LPP]) and mucosal regions (mucosal LP [MLP]). Several existing patient-reported outcome measures (PROMs) were identified for potential use in LP clinical development programs. This study aimed to assess the content validity and psychometric measurement properties of the Dermatology Life Quality Index (DLQI), Epworth Sleepiness Scale (ESS), Scalpdex and Oral Lichen Planus Symptom Severity Measure (OLPSSM) in an LP population.

METHODS

Patients completed the PROs at various time points as part of an international Phase 2 clinical study in adults with MLP (n = 37), LPP (n = 37) and CLP (n = 37). Test-retest reliability, construct validity and sensitivity to change were assessed. In addition, qualitative cognitive debriefing interviews were conducted with adults with MLP (n = 20), LPP (n = 19) and CLP (n = 19) in the USA and Germany to examine the PROM content validity.

RESULTS

The DLQI demonstrated adequate reliability and validity, although its ability to detect change was modest and most items were considered not relevant in qualitative interviews. The ESS had good reliability but limited evidence of validity and ability to detect change. Conceptual relevance varied according to the qualitative interview data. The Scalpdex was miscellaneous across domains, but the 'Symptoms' domain performed well overall. Overall, Scalpdex concepts were reported as relevant by most LPP patients interviewed. The OLPSSM demonstrated good psychometric properties and strong evidence of content validity.

CONCLUSIONS

The psychometric and qualitative findings support the use of the OLPSSM and Scalpdex within specific LP subtypes but cautioned use of the DLQI. Administration of the ESS is not recommended in LP because of its poor psychometric performance. Given these limitations, further validation of non-specific disease measures is needed and/or the development of additional LP-specific PROMs.

TRIAL REGISTRATION

NCT04300296.

Correlations between schizophrenia and lichen planus: a two-sample bidirectional Mendelian randomization study

Background

Several existing studies have shown a correlation between schizophrenia and lichen planus (LP). However, the causality of this relationship remains uncertain. Thus, this study aimed to examine the causal association between schizophrenia and LP.

Methods

A two-sample Mendelian randomization (MR) study was carried out to investigate whether schizophrenia is causally related to LP and vice versa, and genetic variants in this study were taken from previous genome-wide association studies. We used the inverse variance weighted (IVW) method as the main analysis. Furthermore, several sensitivity analyses were performed to assess heterogeneity, horizontal pleiotropy, and stability.

Results

Our results show that schizophrenia has a protective effect on LP (OR = 0.881, 95%CI = 0.795-0.975, p = 0.015). Conversely, we observed no significant relationship between LP and schizophrenia in reverse MR analysis (OR = 0.934, 95%CI = 0.851-1.026, p = 0.156).

Conclusion

Our two-sample Mendelian randomization study supports a significant causal relationship between LP and schizophrenia and finds that schizophrenia can reduce the incidence of LP. This is in contrast to previous findings and provides new insights into the relationship between LP and schizophrenia, but the exact mechanism needs further investigation.

Comorbidity in patients with Lichen sclerosus: a retrospective cohort study

Lichen sclerosus (LS) is a chronic lymphocyte mediated inflammatory mucocutaneous disease of unknown aetiology with a predilection for the anogenital region, and affecting both sexes. The disease is characterized by pain, intolerable itching and scarring. In late stages of LS, disfiguring scarring can drastically alter the structural anatomical architecture of the genitals. The association between genital LS and different malignant tumours is a concern that needs to be further investigated. An association between LS and several autoimmune diseases has been confirmed in recent studies. All registered citizens of Region Jönköping, Sweden were included in the present study. Patients diagnosed with LS (n = 5680) between 2001 and 2021 were identified using ICD-10 code L90.0 and selected as cases. All other individuals (n = 362 568) served as controls. Odds ratios (ORs) for the selected comorbidity were calculated and adjusted for age and sex. The cumulative incidence of LS for the entire population over a 20-year period was 1.54% (15.4 per 1000 people). The cumulative incidences over a 20-year period for females and males were 2.13% and 0.97%, respectively. This study confirmed the association between LS and vulvar cancer (OR = 17.4; 95% CI 12.1-25.3), penis cancer (OR = 9.1; 95% CI 4.3-18.9), prostate cancer (OR = 2.0; 95% CI 1.6-2.4) and breast cancer (OR = 1.6; 95% CI 1.4-1.8). LS was also associated with Crohn´s disease (OR = 2.0; 95% CI 1.6-2.6) and diabetes mellitus type 1 (OR = 1.9; 95% CI 1.6-2.1). The present study revealed novel important data regarding the association of LS with cancer and autoimmune diseases, emphasising the importance of sufficient treatment and follow-up of patients with LS. However, future studies are needed to confirm these results and the potential role of LS in the development of cancer.

Bidirectional Association between Lichen Planus and Hepatitis C-An Update Systematic Review and Meta-Analysis

Lichen planus (LP) is a chronic, inflammatory mucocutaneous disorder associated with systemic diseases such as hepatitis C (HCV). The objective of this study is to evaluate the association between LP and HCV bidirectionally through a systematic review and meta-analysis. A comprehensive search of studies published was performed in the databases of PubMed, Embase, and Web of Science. Out of 18,491 articles, 192 studies were included. The global prevalence of HCV positive (HCV+) in LP patients registered from 143 studies was 9.42% [95% confidence interval (CI), 7.27-11.58%], and from these, 84 studies showed HCV+ 4-fold more frequent in LP than a control group (OR, 4.48; 95% CI, 3.48-5.77). The global prevalence of LP in patients HCV+ recorded from 49 studies was 7.05% (95% CI, 4.85-9.26%), and from these, 15 registered a 3-fold more LP in HCV (OR, 3.65; 95% CI, 2.14-6.24). HCV+ in LP patients showed great geographic variability (OR, 2.7 to 8.57), and the predominantly cutaneous location was higher (OR, 5.95) than the oral location (OR, 3.49). LP in HCV+ patients was more frequent in the Eastern Mediterranean (OR, 5.51; 95% CI, 1.40-15.57). There is a higher prevalence of HCV+ in LP and vice versa than in the control group, especially in certain geographical areas that should be taken into consideration when doing screening in countries with an upper prevalence of HCV among the general population.

Patient Experience of Lichen Planus: A Qualitative Exploration of Signs, Symptoms, and Health-Related Quality of Life Impacts

INTRODUCTION

Lichen planus (LP) is an inflammatory skin disorder that can present in various forms across the body, including lesions on the skin (cutaneous LP [CLP]), scalp (lichen planopilaris [LPP]), and mucosal regions (mucosal LP [MLP]). Qualitative exploration of the patient experience of LP, notably symptoms and impacts on health-related quality of life (HRQoL), is limited. A scarcity of research was also identified relating to emotional wellbeing impacts of CLP patients. Two qualitative studies were conducted with LP patients to address these gaps.

METHODS

Study 1 consisted of exit interviews conducted with a subset of adult patients with MLP (n = 5), CLP (n = 4), and LPP (n = 4) enrolled in an LP clinical study in the United States (US) to explore the patient experience. Study 2 consisted of independent qualitative interviews conducted with adult CLP patients (n = 13) from the US and Germany to further explore impacts on emotional wellbeing.

RESULTS

Exit interviews found that itch , pain, and skin lesions were most frequently reported as signs/symptoms of LP. Itch and skin lesions were experienced across all LP subtypes, while pain was only reported by CLP and MLP patients. These signs/symptoms impacted HRQoL including emotional wellbeing (frustration, embarrassment), daily activities (oral hygiene, clothing options), social functioning (intimacy, social activities), and physical functioning (chewing/swallowing, opening/moving mouth). Impacts on activities of daily living (ADL) and physical functioning were mostly experienced by MLP patients. Independent qualitative interviews, which further explored impacts of CLP on patients' emotional wellbeing, identified frustration, worry, sadness, embarrassment, and depression as the most frequently experienced.

CONCLUSION

The findings contribute to the literature by providing qualitative insights into signs/symptoms and HRQoL impacts of LP, from the adult patient perspective. The findings also highlight the importance of considering assessment of HRQoL impacts in future clinical LP research, particularly impacts on emotional wellbeing when selecting instruments for assessment of HRQoL in the CLP population.

TRIAL REGISTRATION

NCT04300296.

Dermatoscopy of Cutaneous Lichen Planus - Attempt to Translate Metaphoric Terminology Into Descriptive Terminology

INTRODUCTION

Dermatoscopy is gaining appreciation in assisting the diagnosis of inflammatory dermatoses (inflammoscopy). Lichen planus (LP) is a common inflammatory skin disease with characteristic dermatoscopic features. Over the last few years, numerous articles were published on the dermatoscopy of LP and a high number of terms have been used to describe the dermatoscopic features of this disease.

OBJECTIVES

The objective of this study was to review the literature on the dermatoscopy of LP and to re-evaluate the published descriptions in the light of the 2019 expert consensus on the terminology of dermatoscopy for non-neoplastic skin diseases.

METHODS

We searched the PubMed database using the keywords 'lichen planus and dermatoscopy', 'lichen planus and dermoscopy', 'lichen planus and epiluminescence microscopy', and 'lichen planus and inflammoscopy'.

RESULTS

Of 408 articles retrieved, we selected 67 articles for full-text review, and finally included 58 articles, mostly case reports or small case series, comprising 572 patients with LP. We identified 118 different terms or short descriptions that were used to characterize the dermatoscopy of LP and redescribed them according to International Dermoscopy Society consensus paper. Frequently, authors applied various terms or descriptions to variants of the same feature. Although reported under different designations, Wickham striae were the most consistent dermatoscopic feature of LP. Other characteristics of LP, such as vascular patterns, pigmented structures and follicular findings were less consistent or depended on skin type, anatomic site, disease stage and applied treatment.

CONCLUSIONS

While Wickham striae are the single most important clue for the diagnosis, other dermatoscopic characteristics of LP are less consistent. Based on the descriptions published in the literature we established a dictionary of useful terms for the description of LP that is consistent with the terminology suggested by the recent consensus conference.

Skin-infiltrating T cells display distinct inflammatory signatures in lichen planus, bullous pemphigoid and pemphigus vulgaris

Introduction

We here thought to dissect the inflammatory signature in lesions of three skin disorders, which show a common adaptive immune response against autoantigens of the skin but are characterized by diverging clinical phenotypes. Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are type-2-dependent, IgG autoantibody-driven blistering disorders of mucous membranes and skin, which target desmoglein (Dsg)3 and bullous pemphigoid (BP)180, respectively. In contrast, lichen planus (LP) is a common chronic inflammatory disease of the skin and mucous membranes with a pronounced dermal T cell infiltrate. We previously identified peripheral type 1 and 17 T cell responses against Dsg3 and BP180 in a cohort of LP patients strongly suggesting that the underlying inflammatory T cell signature may drive the evolving phenotype.

Methods

Paraffin-embedded skin biopsies from well-characterized patients with LP (n=31), BP (n=19), PV (n=9), and pemphigus foliaceus (PF) (n=2) were analysed. Areas with the most prominent inflammatory infiltrate were excised with punch biopsies and tissue microarrays (TMA) containing multiple biopsies were created. Using multicolor immunofluorescence, the inflammatory infiltrate was stained with antibodies against multiple cellular markers, i. e. CD3ϵ, CD4, CD15, TCR-δ, the cytokine IL-17A, and the transcription factors, T-bet and GATA-3.

Results

In LP, there was a higher number of CD4+ T cells expressing T-bet compared to GATA-3. In contrast, CD4+ T cells in PV and BP skin lesions more frequently expressed GATA-3 than T-bet. IL-17A+ cells and IL-17A+ T cells were found to a similar extent in all the three disorders. IL-17A+ granulocytes were more predominant in BP than in LP or PV. Of note, the majority of IL-17A+ cells in LP were neither T cells nor granulocytes.

Discussion

Our findings in inflammatory skin infiltrates clearly show a predominant type 1 signature in LP in contrast to a preponderance of type 2 T cells in PV and BP. In contrast to LP, granulocytes and to a much lesser extent CD3+ T cells were a cellular source of IL-17A in BP and PV. These data strongly suggest that different inflammatory cell signatures drive evolving clinically diverse phenotypes of LP, PV and BP despite common target antigens of the skin.

Human papilloma virus-16-specific CD8+ T-cell expansions characterize different clinical forms of lichen planus and not lichen sclerosus et atrophicus

Lichen planus (LP) is a cutaneomucosal chronic inflammatory disease characterized by a CD8+ cytotoxic T-lymphocytes (CTL) infiltrate. In erosive oral LP, we found HPV16-specific activated CTL in lesions, supporting a pathogenic contribution of HPV16. Here, we investigated whether a similar scenario occurs in other clinical forms of LP and in lichen sclerosus et atrophicus (LSA), another chronic disease also affecting the mucosa and/or the skin. Blood CTL from LP and LSA patients expressed significant higher levels of granzyme B, perforin and CD107a proteins than healthy donors. Expansions of TCRVß3+ CTL, with presence of TCR clonotypes identical to those previously detected in erosive oral LP, were found both in blood and mucosal/skin lesions of LP, and not of LSA patients. These expansions were enriched with HPV16-specific CD8+ T-cells as shown by their recognition of the E711-20 immunodominant epitope. In LSA patients, the peripheral repertoire of CTL was oligoclonal for TCRVß6+ CTL. Finally, although patients with LP and LSA have developed antibodies against HPV16 capsid L1, antibodies against HPV16 E6 were only observed in patients with LP. Overall, our data collectively suggest an involvement of HPV16-specific CTL in different clinical forms of LP, not only in erosive oral LP, while a different scenario operates in LSA.

Characteristics, comorbidities, and treatment practices of lichen planus in Northern Finland: A register-based study among 619 subjects

Background and Aims

Lichen planus (LP) is a common itching skin disease where lesions appear on the skin and mucous membranes. However, the epidemiology of LP is not yet sufficiently understood. The aim of this study was to retrospectively map out the characteristics, comorbidities and treatments of patients diagnosed with LP.

Methods

This is a retrospective hospital patient registry-based study performed between 2009 and 2021 in a secondary care hospital (Oulu University Hospital) in Northern Finland. All patients with recorded diagnosis of LP were included in the study. Characteristics, comorbidities, and treatments of LP patients were studied.

Results

In total, 619 patients were verified from the hospital health records. The mean age of patients was 54.2 years and the majority were female (58.3%). Most of the patients had symptoms in more than two skin areas (mean 2.7 skin areas), lower limbs being the most common site (74.0%). A third of patients (34.7%) had oral LP lesions. Nearly fifth (19.4%) of the subjects had a history of previous LP. Of comorbidities found among LP subjects, obesity (22.5%), malignancies (19.4%), depression (12.8%), and thyroiditis (12.4%) were seen more often than in general Finnish population. The most used form of treatment was topical corticosteroids (97.6%), followed by phototherapy 26.8%. Systemic treatments such as prednisolone and methotrexate had been used in 7.6% and 1.1% of the patients, respectively.

Conclusion

LP patients had a heightened risk for several comorbidities, which should be considered when managing patients with LP.

Risk of Prediabetes and Diabetes in Oral Lichen Planus: A Case-Control Study according to Current Diagnostic Criteria

OBJECTIVE

To estimate the prevalence of prediabetes and diabetes in patients with oral lichen planus (OLP).

METHODS

Prospective cohort, including consecutive patients diagnosed clinically and histologically with OLP from 2018 to 2022. Patients and controls were matched by age and gender. Fasting plasma glucose value collection from all patients. Multivariate regression analysis evaluated the relationship between prediabetes and diabetes variables according to current diagnostic criteria.

RESULTS

The sample comprised 275 patients (207 women; 75.3%), mean age 59.60 ± 12.18 years for both groups. Prediabetes was diagnosed according to the American Diabetes Association (ADA, 100-125 mg/dL), in 21.45% of OLP patients (59/275) and 14.55% (40/275) of control patients (p = 0.035). Patients with the atrophic-erosive form exhibited stronger association with taking oral antidiabetics (p = 0.011). Multivariate analysis showed that being over >60 years and having a cutaneous location was associated with ≥3 sites (OR 1.81 and OR 2.43). ADA prediabetes and oral antidiabetics drugs increased the probability of OLP (OR 1.60 (1.04-2.51), p = 0.03 and OR 2.20 (1.18-4.69), p = 0.017) after adjustment for sex and age.

CONCLUSIONS

Because glycemia 100-125 mg/dL was associated with OLP, testing serum fasting plasma glucose seems reasonable in order to prevent development of diabetes and deal with possible complications until new studies are complete.

[Esophageal Lichen Planus - An Underdiagnosed Disease]

An involvement of the esophagus in patients with lichen planus was described for the first time in 1982. Ever since, it has been seen as a rarity. However, studies over the last 10 years have shown a higher prevalence than expected. It may even be supposed that esophageal lichen planus (ELP) is more common than eosinophilic esophagitis. ELP mostly affects middleaged women. The principal symptom is dysphagia. Endoscopically, ELP is characterized by denudation and tearing of the mucosa, trachealization and hyperkeratosis and esophageal stenosis may occur in patients with long courses of the disease. Histologic findings including mucosal detachment, T-lymphocytic infiltrate, intraepithelial apoptosis (civatte bodies) and dyskeratosis are crucial. Direct immunofluorescence shows fibrinogen deposits along the basement membrane zone. So far, there is no well-established therapy but a treatment with topic steroids is effective in 2/3 of the patients. Common therapy of lichen planus of the skin seems to be ineffective for treatment of ELP. Symptomatic esophageal stenosis should be endoscopically dilated. ELP joins the group of "new" immunologic diseases of the esophagus.