Lichen planus and lichenoid dermatoses: Clinical overview and molecular basis

Lichen Planus: A Cross-Sectional Evaluation of US Dermatologists' Comorbidity Screening and Management Patterns

INTRODUCTION

Lichen planus (LP) is a chronic inflammatory dermatosis affecting up to 0.91% of the US's population. LP is associated with various comorbid conditions, among them autoimmune conditions. LP has various treatment strategies, although none are US Food and Drug Administration (FDA)-approved; this is further complicated by the lack of any clinical or expert guidelines. This study aimed to explore dermatology practitioners' comorbidity screening patterns and treatment practices for management of LP.

METHODS

An institutional review board (IRB)-approved, anonymous survey was distributed to members of the ODAC Conference listserv, targeting dermatology practitioners. The survey collected data on demographics, comorbidity screening, and treatment strategies.

RESULTS

A total of 406 respondents (17.4% response rate) participated. Hepatitis C virus was the most screened for condition (91.0%), despite its overall low prevalence in patients with LP. Screening rates for highly prevalent comorbidities such as hypertension (10.1%), dyslipidemia (9.7%), depression (18.7%), and anxiety (17.3%) were low. Importantly, almost one-third (32.5%) of respondents reported performing no screening for any comorbid conditions. Topical corticosteroids were the most prescribed therapy (97.8%), followed by topical calcineurin inhibitors (67.7%) and intralesional corticosteroids (64.8%), consistent with high-level evidence for their use in LP treatment. Phototherapy and systemic treatments, including oral immunosuppressants and retinoids, were less frequently utilized despite strong evidence supporting their use.

CONCLUSION

These data highlight gaps in the comorbidity screening practices among dermatology practitioners managing LP, with significant underscreening for prevalent conditions. While respondents commonly relied on some evidence-based topical treatments, there is notable underutilization of systemic treatments for moderate to severe disease. These results emphasize the need for clinical guidelines for LP management, aiming to enhance patient care and outcomes.

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.

Causal association of the skin microbiome with human infertility: insights from a bidirectional two-sample Mendelian randomization

Infertility is a disorder characterized by the inability to achieve a clinical pregnancy after 12 months of regular and unprotected sexual activity. Affecting 8-12% of the global population, with the continuous progress of microbial research in recent years, a variety of microorganisms may be associated with the onset of infertility. We therefore used a two-sample MR Analysis to investigate the association between skin microbes and infertility. we used preprocessed exposure data to correlate infertility measures (infertility in women, associated with anovulation; Female infertility, cervical infertility, vaginal infertility, other infertility or unknown causes; Female infertility, fallopian tube origin; ED; Based on this, the positive results were subjected to horizontal pleiotropy analysis and heterogeneity analysis. Finally, Steiger test was performed to confirm the absence of reverse causality. The data used in this study were obtained from the published GWAS data sets. skin microbiota from the study conducted by Moitinho-Silva et al., and the exposure from the Finn. In this study, we found a positive causal association between Lactobacillales, Clostridiales, Pseudomonadales, and Moraxellaceae and female infertility and anovulation by MR Analysis of two samples. Enhydrobacter, Betaproteobacteria have a negative causal association with female infertility and anovulation. Lactobacillales and Alphaproteobacteria had positive causal association with female infertility, cervical infertility, vaginal infertility, other infertility or unknown causes. There was a negative causal association between Haemophilus and female infertility, cervical infertility, vaginal infertility, other infertility or unknown causes. Alphaproteobacteria are positively correlated with female infertility and fallopian tube origin. Bacteroidetes is negatively correlated with female infertility and fallopian tube origin. Rhodobacteraceae, Clostridiales and Flavobacteriaceae had a negative causal association with male infertility. Corynebacterium had a positive causal association with ED, and Micrococcus had a negative causal association with ED. Our study reveals a causal association between skin microbiota and infertility, and provides a theoretical basis for the inclusion of skin microbiota in the prevention and treatment of infertility. To the best of our knowledge, our study is the first MR Analysis to explore the potential causal association between skin microbiota and infertility. On this basis, we make a reasonable hypothesis that skin microbes cause infertility, and propose possible mechanisms. Our research contributes to the prevention and treatment of clinical infertility.

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.

The Steroid Veil: Complications in Identifying Lupus

While topical steroids are an invaluable tool used for the treatment of pruritic rashes, they can also complicate attempts at a definitive diagnosis. The temporal association between steroid use and biopsy must be taken into account when investigating the underlying etiology of such rashes. In patients with a history of dermatologic disease with the onset of a new rash, management should include a biopsy, if deemed necessary for diagnosis, followed by a prescription of topical steroids for symptomatic treatment. A 63-year-old male with a history of psoriasis presented with a new-onset pruritic, erythematous-to-violaceous rash on sun-exposed areas. The final diagnosis of subacute cutaneous lupus erythematosus (SCLE) was delayed due to the use of topical steroids on cutaneous eruptions before presentation in the clinic for biopsy. Diagnosis of SCLE can be difficult, especially for primary care providers who do not see the initial presentation regularly, as cutaneous findings can be variable in presentation. However, recurrent eruptions in similar photo-distributed locations should alert providers of a potential underlying diagnosis and prompt referral for dermatologic evaluation should be suggested. Thorough personal and family history should be taken and photographs of the rash should be documented in the patient's chart for future reference. Ultimately, biopsy is the gold standard diagnostic method for evaluating the etiology of new-onset rash. When there is suspicion of an underlying disease beyond idiopathic contact or irritant dermatitis, a biopsy should be considered as the next best step in management.

Immune Checkpoint Inhibitor-Associated Cutaneous Adverse Events: Mechanisms of Occurrence

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs' unique molecular action that is mainly mediated by the activation of cytotoxic CD4+/CD8+ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs.

Glycyrrhizin alleviates the toxicity of hydroxychloroquine in treating oral lichen planus by occupying heat shock protein 90 alpha

BACKGROUND

Oral lichen planus (OLP) is a common chronic inflammatory disease with the potential of malignant transformation. Hydroxychloroquine (HCQ), derived from quinine originating from Cinchona spp. bark, is a commonly prescribed off-label for OLP. However, it lacks robust evidence-based medicine practice, as well as theoretical guidance for its pharmacodynamic targets and for mitigating adverse reactions.

PURPOSE

To compare the efficacy of HCQ with first-line treatment prednisone for treating severe erosive OLP and to identify compatible phytomedicine that is reasonably available based on elucidating the molecular targets related to clinical benefits and adverse reactions.

METHODS

We performed a single-center, randomized, investigator-blinded, positive-controlled, non-inferiority trial. Patients who met the enrollment criteria were randomly allocated (1:1) to receive either HCQ or prednisone therapy for 4 weeks and follow-up for 3 months. The primary outcome measures included reductions in the erosion area and pain level. Potential targets of HCQ and associated toxic effects in treating OLP were identified through in silico analysis and validated through histological evaluation. Common hepatoprotective agents, including glycyrrhizin and total glucosides of peony, were analyzed for their potential targets. Then tri-molecular docking study was performed to screen available phytomedicine agent for alleviating adverse reaction of HCQ. Finally, in vitro experiments were performed to validate these targeted effects.

RESULTS

A total of 62 patients were enrolled from January 2021 to August 2023. After a 4-week treatment, there's no significant difference between patients receiving HCQ and PDN in the reduction of erosion area (median, 44 vs 58.5; HCQ - PDN difference: -11; 95 % CI, -39 to 13; p = 0.438) or pain level (median, 3 vs 3; HCQ - PDN difference: 0; 95 % CI, -1 to 1; p = 0.925). Heat shock protein 90 (HSP90) alpha and beta were identified as potential therapeutic targets of HCQ for treating OLP, while HSP90α is also associated with the adverse reactions of HCQ. The expressions of HSP90α and HSP90β in OLP tissue were significantly reduced compared to normal tissue. The phytomedicine glycyrrhizin was selected due to its specific interaction with the GLY-181 site of HSP90α, same as HCQ's toxic targets. HCQ exerted pro-proliferative and anti-inflammatory effects in vitro. And both HCQ and glycyrrhizin treatment restore the expression of HSP90β, while HCQ treatment also restored the expression of HSP90α.

CONCLUSIONS

HCQ was not inferior to prednisone for treating severe erosive OLP, suggesting it as an alternative to first-line treatment. Integrating phytopreparation glycyrrhizin into conventional HCQ treatment in OLP can help detoxify by occupying the HSP90α binding site.

Nail Lichen Striatus and Its Differential Diagnoses

Background

Lichen striatus (LS) is a benign, mostly self-limiting dermatological condition, primarily affecting the skin, and sometimes the nails. It is characterised by the sudden onset of a band-like rash, typically following Blaschko lines. The exact cause of LS is not well established, but it is believed to be an abnormal immune response to the altered keratinocyte clone after a triggering event.

Summary

Although nail LS is regarded as rare, it is probably underreported. Single-visualised nail dystrophy, especially partial involvement of the nail, with or without skin rash, should prompt the LS diagnosis among differentials. Onychoscopy might be helpful to better visualise the clinical signs. Nail dystrophy often has a prolonged course even after the resolution of skin lesions. Topical steroids, calcineurin inhibitors, and intralesional steroid injections might be an option for symptomatic patients or for severe and prolonged nail dystrophy.

Key Messages

(i) Single nail involvement, nail changes located on one portion of the nail, and the presence of typical linear band-like skin rash should prompt the LS diagnosis. (ii) Onychoscopy might be helpful to better visualise the clinical signs and to avoid unnecessary biopsies. (iii) Nail unit biopsy should be performed if the diagnosis is uncertain to exclude nail involvement of more severe and progressive disease course like nail lichen planus and/or nail unit tumours.

Lichen planus-the role of age and gender in clinical appearance and treatment : A narrative review

Lichen planus is a common pruritic inflammatory disorder of the skin with an autoimmune background. It affects < 1% of the general population. The disease has significant comorbidities that must be considered in a holistic approach. Skin and skin adnexa, mucosa, eyes, and the esophagus may be affected. There are various clinical subtypes in addition to classical cutaneous lichen planus. These subtypes depend on age and gender. Nail involvement can result in functional and psychological impairment. Lichen planopilaris in adults leads to irreversible cicatrical alopecia. Erosive and ulcerated lichen planus of the mucosa carries an increased risk of malignant transformation, at least in adults. Treatment must consider the affected area, the severity of disease, age, gender, and comorbidities.

CXCL9, CXCL10, and CCL19 synergistically recruit T lymphocytes to skin in lichen planus

Lichen planus (LP) is a chronic, debilitating, inflammatory disease of the skin and mucous membranes that affects 1%-2% of Americans. Its molecular pathogenesis remains poorly understood, and there are no FDA-approved treatments. We performed single-cell RNA sequencing on paired blood and skin samples (lesional and nonlesional tissue) from 7 patients with LP. We discovered that LP keratinocytes and fibroblasts specifically secrete a combination of CXCL9, CXCL10, and CCL19 cytokines. Using an in vitro migration assay with primary human T cells, we demonstrated that CCL19 in combination with either of the other 2 cytokines synergistically enhanced recruitment of CD8+ T cells more than any individual cytokine. Moreover, exhausted T cells in lesional LP skin secreted CXCL13, which, along with CCL19, also enhanced recruitment of T cells, suggesting a feed-forward loop in LP. Finally, LP blood revealed decreased circulating naive CD8+ T cells compared with that in healthy volunteers, consistent with recruitment to skin. Molecular analysis of LP skin and blood samples increased our understanding of disease pathogenesis and identified CCL19 as a new therapeutic target for treatment.

Immunohistochemical examination of immunoreactivity of transient receptor potential melastatin 2, glutathione peroxidase 4 and spexin in lichen planus

BACKROUND

In this study, we aimed to investigate the potential contributions to the disease by examining the immunoreactivities of SPX in LP-affected skin tissue using immunohistochemical methods, in light of its recent prominence as a molecule related to diabetes mellitus, along with apoptosis and ferroptosis mediated by GPX4 and TRPM2 channels facilitating oxidative stress-induced cell death.

OBJECTIVE

This research explored the immunohistochemical expressions of TRPM2, GPX4, and SPX in Lichen Planus (LP) patients compared to healthy individuals.

MATERIALS AND METHODS

Forty skin samples were collected, split equally between LP patients and healthy controls, excluding those with other conditions. Samples underwent immunohistochemical staining for TRPM2, SPX, and GPX4, using secondary antibodies and chromogens AEC or DAB. Histoscores were calculated based on staining diffusiveness and severity. Statistical analyses were performed with SPSS 22.0, using t-tests and ANOVA, with significance set at p < 0.05.

RESULTS

There were no demographic differences between groups (p > 0.05). LP patients showed significantly lower TRPM2 and GPX4 histoscores and higher SPX histoscores compared to controls (TRPM2 and GPX4: p < 0.001, SPX: p < 0.001). Gender and age did not affect histoscores significantly.

CONCLUSIONS

Findings suggest TRPM2, GPX4, and SPX play roles in LP pathogenesis, indicating a need for further molecular studies to clarify their involvement. This contributes to understanding LP beyond the traditional apoptosis perspective.

[Delayed hypersensitivity reactions to drugs: Group Report of the Drug Allergy Committee of the Mexican College of Clinical Immunology and Allergy (CMICA).]

BACKGROUND

Adverse drug reactions are defined as unexpected reactions, either derived from the pharmacokinetics of the treatment (Type A) or as a host immune response (Type B), resulting in harmful or undesirable manifestations in the patient following the administration of pharmacological therapy. Type B reactions are less defined and are considered a result of hypersensitivity to pharmacological treatment, categorized as immediate (within 1 to 6 hours after exposure) and delayed or non-immediate (occurring 6 hours after exposure).

OBJECTIVE

A review to describe the immunological mechanisms of delayed hypersensitivity reactions to drugs.

METHODS

A search of major medical databases on delayed hypersensitivity reactions to drugs was conducted. The review was limited to articles published in the period between 2013 and 2023, taking into consideration articles written in English and Spanish.

RESULTS

The terms defining delayed hypersensitivity reactions to drugs, their classification, clinical manifestations, diagnosis, treatment algorithms, and prognosis.

CONCLUSIONS

Adverse drug reactions represent a challenge for the specialist physician, with a complex pathophysiology. A prompt diagnosis and treatment focused on the drug phenotype and its immunological expression are required to provide a multidisciplinary approach.

Lichen Planus: What is New in Diagnosis and Treatment?

Lichen planus (LP), an idiopathic, multifaceted chronic inflammatory disease with a heterogeneous clinical presentation, affects approximately 0.5-1% of the population. The various clinical manifestations of LP fall into three broad categories, namely cutaneous, appendageal, and mucosal, with further subclassification depending on the morphology and distribution patterns of individual lesions. There is mounting evidence that LP has systemic associations, including autoimmune conditions, glucose intolerance, dyslipidemia, and cardiovascular disorders. Cutaneous hypertrophic and mucosal forms of LP are at a heightened risk for malignant transformation. Familiarity with these potential associations in conjunction with long-term follow-up and regular screening could lead to a timely diagnosis and management of concomitant conditions. In addition, the frequent quality of life (QoL) impairment in LP underscores the need for a comprehensive approach including psychological evaluation and support. Several treatment strategies have been attempted, though most of them have not been adopted in clinical practice because of suboptimal benefit-to-risk ratios or lack of evidence. More recent studies toward pathogenesis-driven treatments have identified Janus kinase inhibitors such as tofacitinib, phosphodiesterase-4 inhibitors such as apremilast, and biologics targeting the interleukin-23/interleukin-17 pathway as novel therapeutic options, resulting in a dramatic change of the treatment landscape of LP. This contemporary review focuses on the diagnosis and management of LP, and places emphasis on more recently described targeted treatment options.

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.

Differential diagnosis of contact dermatitis: A practical-approach review by the EADV Task Force on contact dermatitis

The diagnosis of eczema ('dermatitis') is mostly clinical and depends on the clinical history and exploratory objective findings (primary lesions, patterns). Contact dermatitis remains as an important condition in the group of eczematous disorders, with important socioeconomic and occupational relevance. Although irritant and allergic contact dermatitis have a different pathogenesis, both are characterized by a rather typical morphology, are triggered by external factors and tend to occur primarily in the area of contact with the exogenous agent. In addition, allergic and irritant dermatitis may also co-exist. The importance of diagnosing contact dermatitis, especially when allergic in nature, is both due to the possibility of avoiding the trigger, and due to its role in aggravating other skin conditions. Nevertheless, the heterogeneity of clinical presentations in daily practice may pose an important challenge for the suspicion and correct diagnosis of contact dermatitis. Furthermore, other conditions, with different pathogenesis and treatment, may clinically simulate contact dermatitis. The Task Force aims to conduct a review of the unifying clinical features of contact dermatitis and characterize its main clinical phenotypes, and its simulators, in order to contribute to an early suspicion or recognition of contact dermatitis and enable a correct differential diagnosis.

The impact of lipidome on five inflammatory skin diseases: a Mendelian randomization study

OBJECTIVE

Two-sample Mendelian randomization (TSMR) was employed to examine the association between lipidome and five inflammatory skin diseases.

METHOD

To evaluate the association between various molecular subtypes of lipidome and the risk of five inflammatory skin diseases, we analyzed a comprehensive GWAS dataset comprising 179 lipidome. The Two-Sample Mendelian Randomization (TSMR) method was employed to investigate causal relationships. Heterogeneity and pleiotropy were assessed using Cochran's Q test, MR-Egger intercept test, and MR-PRESSO global test. Additionally, a sensitivity analysis was conducted to evaluate the influence of individual single nucleotide polymorphisms on Mendelian Randomization study.

RESULTS

Using 179 serum lipidome as exposures and five common inflammatory skin diseases as outcomes, we investigated their associations in this large-scale study. Our findings reveal significant impacts of glycerophospholipids, glycerolipids, and sphingomyelins on inflammatory skin diseases. Glycerophospholipids were protective against pemphigus but predominantly posed risks for other inflammatory skin diseases. Specifically, phosphatidylcholine (16:0_0:0) exhibited the most significant risk association with lichen planus (OR = 1.25, 95% CI 1.11-1.40, P < 0.001). Conversely, glycerolipids showed no effect on lichen planus but were protective against pemphigus while potentially posing risks for other conditions. Triacylglycerol (46:2) showed the most substantial risk association with vitiligo (OR = 1.99, 95% CI 1.35-2.93, P < 0.001). Furthermore, sphingomyelins had no effect on atopic dermatitis but posed potential risks for other inflammatory skin diseases. Sphingomyelin (d40:1) notably emerged as a significant risk factor for pemphigus (OR = 1.91, 95% CI 1.37-2.66, P < 0.001).

CONCLUSIONS

This study has elucidated the potential harmful effects of glycerophospholipids, glycerolipids, and sphingomyelins on inflammatory skin diseases, while also providing valuable insights for future research into the pathophysiology, prevention and treatment of these conditions.

Unveiling a Dermatological Rarity: The Enigma of Vulvar Intraepithelial Neoplasia Grade III (HSIL) and the Role of p53 in Its Development

Vulvar intraepithelial neoplasia, also known as VIN, is a non-invasive squamous lesion and precursor of squamous cell carcinoma (SCC) of the vulva. There is no screening test for vulvar intraepithelial neoplasia. Diagnosis of VIN is made clinically and confirmed with a biopsy. We describe a 66-year-old woman with a condyloma-like tumour located in the skin on the vestibule of the vagina. A biopsy sample was taken from the nodule. The definitive diagnosis is supported by the histological examination (VIN III) and immunohistochemical examination of p16(+), p53(+), and a few cell nuclei. The case provides information on the importance of multidisciplinary cooperation. Lifelong surveillance is essential since the resection of individual lesions does not guarantee the prevention of invasive cancer.

COVID-19-Vaccination-Induced Localized Lichen Planus Successfully Treated With Phototherapy

Lichen planus (LP) is an inflammatory autoimmune mucocutaneous disease with different forms and presentations. It mainly affects the skin and oral mucosa but could also affect genital mucosa, nails, hair, and, rarely, the larynx and esophagus. Since the start of the COVID-19 era, multiple cutaneous manifestations related to SARS-CoV-2 infection or vaccination have been reported. Different rare cases of lichen planus were reported after COVID-19 infection and vaccination. This report elaborates on and adds an additional case of localized cutaneous lichen planus (CLP) to the upper extremities, which developed after both doses of the mRNA vaccine and improved after phototherapy.

Lichenoid Drug Eruption Secondary to Adalimumab: A Case Report

Adalimumab, an anti-tumor necrosis factor-α (TNF-α), is widely prescribed for many autoimmune diseases and chronic inflammatory skin diseases such as hidradenitis suppurative, psoriasis, etc. We report a case of lichenoid drug eruption secondary to adalimumab, a rare side effect, in a 62-year-old female with ulcerative colitis. The skin eruption appeared two weeks after initiating adalimumab. A skin biopsy was taken, and the histopathological findings correlated with a lichenoid drug eruption. Although rare, drug-induced lichen planus has been associated with adalimumab. Early recognition and a high index of suspicion are key in the prompt management of these cases. The discontinuation of adalimumab must be carefully weighed against its therapeutic benefits, as the discontinuation might trigger a severe form of inflammation in the primary autoimmune disease being treated. Extreme caution, early intervention, and a multidisciplinary approach are best for the overall well-being and optimal care of the individual.

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.

PA28γ induces dendritic cell maturation and activates T-cell immune responses in oral lichen planus

Oral lichen planus (OLP) is a common chronic inflammatory disease of the oral mucosa, the mechanism of its inflammatory progression has not yet been fully elucidated. PA28γ plays a significant role in a variety of immune-related diseases. However, the exact role of PA28γ in the pathogenesis of OLP remains unclear. Here, we demonstrated that PA28γ is overexpressed in epithelial cells and inflammatory cells of OLP tissues but has no significant relationship with OLP subtypes. Functionally, keratinocytes with high PA28γ expression could induce dendritic cell (DC) maturation and promote the T-cell differentiation into Th1 cells in response to the immune response. In addition, we found that a high level of PA28γ expression is associated with high numbers of infiltrating mature DCs and activated T-cells in OLP tissues. Mechanistically, keratinocytes with high PA28γ expression could promote the secretion of C-C motif chemokine (CCL)5, blocking CCL5 or/and its receptor CD44 could inhibit the induction of T-cell differentiation by keratinocytes with high PA28γ expression. In conclusion, we reveal that keratinocytes with high expression of PA28γ in OLP can induce DC maturation and promote T-cell differentiation through the CCL5-CD44 pathway, providing previously unidentified mechanistic insights into the mechanism of inflammatory progression in OLP.

CO2 laser vaporisation in treating oral lichen planus: A split-mouth randomised clinical trial

OBJECTIVES

This study aimed to compare the effectiveness of carbon dioxide (CO2) laser vaporisation versus intralesional injection of triamcinolone acetonide (TA) in the management of oral lichen planus (OLP).

METHODS

A randomised clinical trial with a split-mouth design was conducted on 16 patients with bilateral symptomatic OLP lesions. One side was treated with CO2 laser vaporisation, and the counterpart was treated with TA intralesional injection. The reticular-erythematous-ulcerative (REU) score, Thongprasom sign scoring (TSS), visual analogue scale (VAS) and lesion area were used to evaluate the lesions at weeks 0, 4 and 9. All participants were followed up for 9 months.

RESULTS

Reduction in the REU, TSS scores and lesion area from baseline to the end of treatment was significantly greater in the CO2 group than in the TA group (p values were 0.001, 0.002 and 0.048 respectively). However, the reduction in VAS score did not differ between the two groups (p = 0.54). The recurrence rate was significantly higher in the TA group than in the CO2 group (75% vs. 31.1%; p = 0.016).

CONCLUSIONS

CO2 laser vaporisation was more effective than TA intralesional injection in managing OLP and decreased recurrence rates.

Efficacy and safety of gut microbiota-based therapies in autoimmune and rheumatic diseases: a systematic review and meta-analysis of 80 randomized controlled trials

BACKGROUND

Previous randomized controlled trials (RCTs) suggested that gut microbiota-based therapies may be effective in treating autoimmune diseases, but a systematic summary is lacking.

METHODS

Pubmed, EMbase, Sinomed, and other databases were searched for RCTs related to the treatment of autoimmune diseases with probiotics from inception to June 2022. RevMan 5.4 software was used for meta-analysis after 2 investigators independently screened literature, extracted data, and assessed the risk of bias of included studies.

RESULTS

A total of 80 RCTs and 14 types of autoimmune disease [celiac sprue, SLE, and lupus nephritis (LN), RA, juvenile idiopathic arthritis (JIA), spondyloarthritis, psoriasis, fibromyalgia syndrome, MS, systemic sclerosis, type 1 diabetes mellitus (T1DM), oral lichen planus (OLP), Crohn's disease, ulcerative colitis] were included. The results showed that gut microbiota-based therapies may improve the symptoms and/or inflammatory factor of celiac sprue, SLE and LN, JIA, psoriasis, PSS, MS, systemic sclerosis, Crohn's disease, and ulcerative colitis. However, gut microbiota-based therapies may not improve the symptoms and/or inflammatory factor of spondyloarthritis and RA. Gut microbiota-based therapies may relieve the pain of fibromyalgia syndrome, but the effect on fibromyalgia impact questionnaire score is not significant. Gut microbiota-based therapies may improve HbA1c in T1DM, but its effect on total insulin requirement does not seem to be significant. These RCTs showed that probiotics did not increase the incidence of adverse events.

CONCLUSIONS

Gut microbiota-based therapies may improve several autoimmune diseases (celiac sprue, SLE and LN, JIA, psoriasis, fibromyalgia syndrome, PSS, MS, T1DM, Crohn's disease, and ulcerative colitis).

Lichen Planus Pigmentosus Inversus: A Case Report of a Man Presenting With a Pigmented Lichenoid Axillary Inverse Dermatosis (PLAID)

Lichen planus pigmentosus is an uncommon subtype of lichen planus and lichen planus pigmentosus inversus is a rare variant of lichen planus pigmentosus. Lichen planus pigmentosus inversus typically presents as hyperpigmented patches or plaques, particularly in the intertriginous areas such as the axillae, the groin and inguinal folds, and in the submammary region. In some patients with lichen planus pigmentosus inversus, the condition can present as a pigmented lichenoid axillary inverse dermatosis (PLAID) when the lesions are in the axillae. A 49-year-old Hispanic man who had hyperlipidemia and diabetes mellitus developed lichen planus pigmentosus inversus and presented with a PLAID. Skin biopsies established the diagnosis of lichen planus pigmentosus inversus. The clinical differential diagnosis of lichen planus pigmentosus inversus includes inherited disorders, primary cutaneous dermatoses, acquired dyschromias, and reactions to topical or systemic medications. Friction in intertriginous areas has been related to the development of lichen planus pigmentosus inversus. Factors that can precipitate lichen planus pigmentosus inversus include not only topical exposure to almond oil, amala oil, cold and cosmetic creams, henna, and paraphenyldiamine but also either topical contact or consumption of mustard oil and nickel. Lichen planus pigmentosus inversus can be associated with autoimmune conditions (hypothyroidism), endocrinopathies (diabetes mellitus), and hyperlipidemia. The dyschromia found in patients with lichen planus pigmentosus inversus is frequently refractory to treatment. Initial management includes removal of potential disease triggers such as eliminating tight clothing to stop friction with the adjacent skin. Topical corticosteroids do not result in improvement; however, topical calcineurin inhibitors such as tacrolimus have been reported to be efficacious. In conclusion, inverse lichen planus and lichen planus pigmentosus inversus can present with a PLAID; whereas topical corticosteroids may be helpful to resolve inverse lichen planus lesions, topical tacrolimus may be useful to improve the dyschromia in lichen planus pigmentosus inversus.

Management of cutaneous adverse events caused by antineoplastic therapies: a single-center experience

INTRODUCTION

Cutaneous adverse events can occur in patients treated with antineoplastic treatments, albeit their incidence has not been defined yet. The clinical presentation of CAEs related to anticancer treatments can vary. The purpose of our study is to characterize skin toxicities during oncological treatments, manage such adverse events to improve patients' quality of life, and ensure therapeutic adherence.

METHODS

We conducted a single-center prospective study which provided the enrollment of all patients referred to the Skin Toxicity Outpatient Clinic for the occurrence of cutaneous adverse events secondary to an ongoing antineoplastic treatment, between July 2021 and June 2023. We analyzed clinical features, and we described our therapeutic approach.

RESULTS

Based on the type of drug assumed, chemotherapy-induced skin toxicity in 24 (38.7%) of the 62 evaluated patients, target therapies in 18 (29.0%), CDK4/6 cyclin inhibitors in 12 (19.4%), and immunotherapy in 6 (9.7%), while skin adverse events secondary to hormone therapy were seen in two patients. The most common cutaneous adverse event in our experience was rosaceiform rash of the face, followed by eczematous rash, hand-foot syndrome, and folliculitis.

CONCLUSION

The present study is aimed at describing the variability and heterogeneity of clinical manifestations of different pharmacological classes used in oncological patients, as well as the different pathogenesis of skin damage. Chemotherapy very frequently causes skin toxicities that are often underestimated by clinicians. Their adequate recognition and optimal treatment lead to total recovery and allow better adhesion to chemotherapy.

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.

Isolated corneal involvement by Lichen Planus - multi-modal evaluation

PURPOSE

To describe a case of ocular Lichen Planus, successfully managed using a multimodal evaulation, including Anterior Segment OCT (AS-OCT).

OBSERVATIONS

A female patient in her forties with a history of cutaneous Lichen Planus presents with blurred vision and burning eye sensation. Anterior segment evaluation revealed bilateral punctate keratitis, stromal haze and subepithelial pigmented dots. AS-OCT was pivotal for diagnosis, showing anterior stromal hyperreflective dots. A diagnosis of ocular Lichen Planus was estabilished and the patient was treated with topical hydrocortisone, with complete subsidence of the complaints.

CONCLUSIONS AND IMPORTANCE

Ocular Lichen Planus can present as isolated corneal involvement independent from severe cicatrizing conjunctivitis. Appropriate and timely treatment can prevent irreversible ocular surface disease. Ophthalmologists should be aware of Lichenoid Tissue Reaction (LTR) disorders, especially in patients with relentless blepharitis and/or ocular surface disease.

Oral Acitretin Plus Topical Triamcinolone vs Topical Triamcinolone Monotherapy in Patients With Symptomatic Oral Lichen Planus: A Randomized Clinical Trial

Importance

Symptomatic oral lichen planus (OLP) can be challenging to treat.

Objective

To compare the efficacy of oral acitretin plus topical triamcinolone acetonide (TAC), 0.1%, with TAC monotherapy in patients with symptomatic OLP.

Design, Setting, and Participants

This monocentric, investigator-initiated, placebo-controlled, investigator- and patient-blinded randomized clinical trial was conducted from December 2018 to June 2020 at the Postgraduate Institute of Medical Education and Research, a tertiary referral center in Chandigarh, India. Sixty-four patients 18 years or older with symptomatic OLP were recruited by consecutive sampling. Data were analyzed from July to December 2020.

Intervention

The patients were randomized to receive either a combination of oral acitretin (25-35 mg/d) and TAC (treatment group) or TAC in combination with placebo (placebo group) for 28 weeks, with an additional 8 weeks of treatment-free follow-up after the end of treatment (36 weeks of total study duration).

Main Outcomes and Measures

The disease severity and treatment response were assessed using Oral Disease Severity Score (ODSS), Oral Health Impact Profile 14 (OHIP-14), and visual analog scale (VAS). The primary aim was to assess the number of patients achieving ODSS-75 (75% reduction in ODSS compared with baseline) in both groups at 28 weeks and at the end of 36 weeks.

Results

Among 64 patients, 31 in the treatment group and 30 in the placebo group completed the study (mean [SD] age, 50.6 [15.2] years vs 49.2 [14.4] years; male-female ratio, 13:19 vs 16:16). Baseline ODSS, visual analog scale, and Oral Health Impact Profile 14 scores were comparable in both groups. In the intention-to-treat analysis, there was a statistically significant higher number of patients achieving 75% or higher reduction in ODSS in the treatment group compared with the placebo group at the end of 28 weeks (28 [88%] vs 15 [47%], a 41 [95% CI, 20-61] percentage point difference between groups; P < .001; Cramér V = 0.47) and 36 weeks (27 [84%] vs 13 [41%], a 43 [95% CI, 23-67] percentage point difference between groups; P < .001; Cramér V = 0.47). Relapses during the posttreatment follow-up of 8 weeks were low among patients in both treatment and placebo groups (1 [3%] vs 2 [6%], a 3 [95% CI, -13 to 7] percentage point difference between groups; P > .99; Cramér V = 0.07).

Conclusion and Relevance

In this randomized clinical trial, the combination of oral acitretin and TAC was more effective than TAC monotherapy in patients with symptomatic OLP.

Trial Registration

Clinical Trial Registry of India Identifier: CTRI/2018/11/016448.

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.

Inverse Lichen Planus Associated With Nail Dystrophy

Lichen planus is a chronic inflammatory disorder affecting skin and mucosal surfaces. There are multiple variants of lichen planus described in the literature. We report a case of inverse lichen planus in a healthy 50-year-old male who presented to our dermatology clinic with multiple violaceous to hyperpigmented patches affecting both axillae and groin for three months. A skin biopsy confirmed the diagnosis of lichen planus. The patient subsequently developed nail dystrophy affecting his fingernails consistent with nail lichen planus. Early recognition and treatment of nail lichen planus is important to prevent irreversible scarring.

Successful treatment of nail lichen planus with tofacitinib: a case report and review of the literature

Nail lichen planus (NLP) is a chronic inflammatory disease of unknown etiology and has been recognized as a nail potentially critical disorder, which can be severe and rapidly worsen with irreversible scarring. Currently, the treatment options are limited based on disease progression. High-potency topical or intralesional corticosteroids are commonly considered first-line therapeutic options; however, these therapies are unsuitable for all patients with NLP, especially those with extensive lesions. As a potential therapeutic target for inflammatory skin diseases, Janus kinase (JAK) inhibitors can suppress both type-1 and type-2 cytokines, thereby reducing the immune response and resultant inflammation. Recent studies have suggested benefit in cutaneous lichen planus and lichen planopilaris with oral JAK inhibitors. Here, we report a case of severe NLP that exhibited a favorable response to tofacitinib treatment. A 41-year-old woman presented to our clinic with a 2-year history of nail dystrophy of all fingers of both hands. The NLP was finally confirmed by histopathology and the above clinical features. After the informed consent signature, tofacitinib monotherapy, 5 mg twice a day, was then begun, and after 6 months, the appearance of her nails had a significant improvement.

Multiple Itchy Erythematous Papules and Plaques Localized to 1 Shin

A woman in her 30s presented with progressive, multiple itchy erythematous to violaceous papules and plaques with milia and a few erosions with partially detached epidermis localized to the left shin. What is your diagnosis?

The role of eosinophils in the differential diagnosis of inflammatory skin diseases

Eosinophils are known to be present in inflammatory skin diseases, but their diagnostic utility is not well established. Upon review of the published status of lesional eosinophils, several categories were identified. 1) Lesional eosinophils highly characteristic such that, in their absence, the pathologist may question the diagnosis. These include arthropod bite reactions and scabies, urticarial dermatitis, and other eosinophilic dermatoses. 2) Lesional eosinophils rare or absent, such that, in their presence, the pathologist may question the diagnosis. These include pityriasis lichenoides, graft versus host disease, and connective tissue disorders. 3) Lesional eosinophils variable and, while in some cases expected, are not required for diagnosis. These include drug reactions, atopic dermatitis and allergic contact dermatitis. 4) Lesional eosinophils variable and not expected but may be seen to a limited extent. These include lichen planus and psoriasis.

Atopic dermatitis in skin of colour. Part 2: considerations in clinical presentation and treatment options

Recent advances in atopic dermatitis (AD) present the condition as a heterogeneous disease of distinct endotypes across ethnic groups. AD in people with skin of colour may appear psoriasiform, lichenoid, scaly or papular, with a violaceous colour and there is a higher prevalence of post-inflammatory dyspigmentation compared with affected individuals of White ethnicity. These differences in clinical presentation may limit the use of AD assessment tools in people with skin of colour, leading to the potential for misdiagnosis and underestimation of severity, particularly in relation to assessment of erythema. Recent targeted therapies for AD have been studied in multiple ethnic groups; however, ethnicity-based subgroup analysis is often not performed. Further research is required to understand whether treatment responses or safety may differ among ethnic groups.

Correlations between gut microbiota and lichen planus: a two-sample Mendelian randomization study

Purpose

Several existing studies have revealed that the occurrence of lichen planus (LP) is relevant to the gut microbiota, and the causal relationship between gut microbiota and LP was analyzed using the Mendelian randomization (MR) method.

Methods

Through the two-sample MR method, single nucleotide polymorphisms (SNPs) relevant to gut microbiota were selected as instrument variables (IVs) to evaluate the causal association between gut microbiota and the risk of LP.

Results

According to the selection criteria of inverse-variance weighted (IVW), six bacterial genera were found to be significantly linked to the initiation of LP; The IVW results suggested that Oxalobacteraceae, Victivallaceae, and Actinobacteria could restrain the initiation of LP, showing protective effects against LP. Desulfovibrio, Veillonella, and Ruminococcus gauvreauii groups were demonstrated to have casual correlations with the onset of LP.

Conclusion

The relationship between gut microbiota and LP was not a single positive or inverse relationship. Investigation of the causal relationship of these gut microbiota with LP could further provide evidence for the intestine-skin axis theory. However, the specific mechanism of microorganisms affecting the skin remains to be clarified. In this paper, the protective effects and mechanisms of Oxalobacteraceae, Victivallaceae, and Actinobacteria on LP require further exploration.

Comparative Evaluation of Pimecrolimus Cream 1% and Triamcinolone Aceonide Paste in Treatment of Atrophic-Erosive Oral Lichen Planus

Objectives

This study was done to assess the effects of pimecrolimus cream 1% and triamcinolone aceonide paste in the treatment of atrophic-erosive oral lichen planus.

Materials and Methods

A total of 100 patients diagnosed both clinically and histopathologically as lichen planus were considered in the present study. Subjects were classified into two groups. Group I: Patients in this group were treated with 1% pimecrolimus cream and Group II: Patients falling under this group were treated with triamcinolone acetonide in 0.1% concentration.

Results

None of the patients reported worsening clinical signs and symptoms. No significant difference in efficacy and reduction in burning sensation of either pimecrolimus or trimcinolone acetonide was present.

Conclusion

Present study found no significant difference in the efficacy of both the agents studied.

Nail lichen planus treatment safety

AREAS COVERED

Topical therapies for nail lichen planus (clobetasol propionate, topical tacrolimus, bath-PUVA), intralesional treatment (triamcinolone), and systemic treatment (corticosteroids, retinoids, small molecule inhibitors (jak/stat inhibitors)), TNF-alpha inhibitors (etanercept), systemic immunomodulators (oral calcineurin inhibitors, mycophenolate mophetil), and antimalarials (chloroquine), each with unique safety profiles and considerations. Herein, we discuss common and uncommon adverse events, as well as utilization for special populations, including pregnant and pediatric patients.

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.

Aberrant inflammasome activation as a driving force of human autoimmune skin disease

Autoimmune skin diseases are understood as conditions in which the adaptive immune system with autoantigen-specific T cells and autoantibody-producing B cells reacting against self-tissues plays a crucial pathogenic role. However, there is increasing evidence that inflammasomes, which are large multiprotein complexes that were first described 20 years ago, contribute to autoimmune disease progression. The inflammasome and its contribution to the bioactivation of interleukins IL-1β and IL-18 play an essential role in combating foreign pathogens or tissue damage, but may also act as a pathogenic driver of myriad chronic inflammatory diseases when dysfunctionally regulated. Inflammasomes containing the NOD-like receptor family members NLRP1 and NLRP3 as well as the AIM2-like receptor family member AIM2 have been increasingly investigated in inflammatory skin conditions. In addition to autoinflammatory diseases, which are often associated with skin involvement, the aberrant activation of the inflammasome has also been implied in autoimmune diseases that can either affect the skin besides other organs such as systemic lupus erythematosus and systemic sclerosis or are isolated to the skin in humans. The latter include, among others, the T-cell mediated disorders vitiligo, alopecia areata, lichen planus and cutaneous lupus erythematosus as well as the autoantibody-driven blistering skin disease bullous pemphigoid. Some diseases are characterized by both autoinflammatory and autoimmune responses such as the chronic inflammatory skin disease psoriasis. Further insights into inflammasome dysregulation and associated pathways as well as their role in forming adaptive immune responses in human autoimmune skin pathology could potentially offer a new field of therapeutic options in the future.

Lichenoid Drug Eruption Induced by Teriflunomide

Lichenoid drug eruptions are a type of skin reaction that is caused by medication and mimics idiopathic lichen planus. Various medications have been known to cause lichenoid drug eruptions, such as antibiotics, anti-convulsants, anti-diabetics, anti-malarials, anti-tubercular drugs, anti-hypertensives, psychiatric drugs, chemotherapeutic agents, diuretics, heavy metals, and non-steroidal anti-inflammatory drugs. Various cutaneous side effects have been reported in association with teriflunomide. We present the case of a patient who developed a lichenoid eruption because of teriflunomide. The dermatologists and neurologists should be aware of these skin side effects.

Lipid Alterations and Metabolism Disturbances in Selected Inflammatory Skin Diseases

Lipidomics is a term used to define the field that analyzes the structure, functions, and interactions of lipids. Inflammatory dermatoses and lipid disturbances are interrelated, especially due to chronic inflammatory conditions. This review discusses lipidomics in selected inflammatory skin diseases: psoriasis, lichen planus, and atopic dermatitis, as well as the less commonly mentioned hidradenitis suppurativa, rosacea, and acne vulgaris. Lipid homeostasis disorders are common; they are especially well-documented in psoriasis, lichen planus, and atopic dermatitis. Future studies are required for better insight into this issue, particularly on the skin lipidome. Understanding lipidomics, in particular skin diseases, increases our knowledge about their pathogenesis, and may become useful in adjusting tailored management for each patient as well establishing prognosis. Noteworthily, it seems advisable to alert doctors to the need to analyze lipid parameters and the complications of abnormal lipid metabolism in dermatological patients, which could decrease their comorbidities and improve the life quality and health condition of dermatological patients.