Hepatitis C virus infections in oral lichen planus: a systematic review and meta-analysis

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.

Coexistence of myasthenia gravis and lichen planus: A case report and systematic review of related case reports from 1971 to 2024

Key Clinical Message

The co-occurrence of myasthenia gravis (MG) and lichen planus (LP) is a rare phenomenon, with only 13 cases reported in the English literature between 1971 and 2024. Patients with MG or LP, regardless of the thymoma status, require close monitoring for other autoimmune diseases.

Abstract

Myasthenia gravis (MG) is an uncommon autoimmune disease, resulting in fatigable muscle weakness in the ocular, bulbar, and respiratory muscles, as well as muscles of the extremities. Lichen planus (LP) is an autoimmune mucocutaneous disease, presenting with pruritic and violaceous plaques on the skin and mucosal surfaces. So far, MG and LP co-occurrence is only reported in anecdotal individuals. This study reports a patient with MG and LP and systematically reviews the English literature on this rare co-occurrence from 1971 to 2024, indicating only 13 cases with similar conditions. A 67-year-old man presented with ocular and progressive bulbar symptoms, a year after being diagnosed with generalized LP. Laboratory evaluations were normal except for the high anti-AchR-Ab titer and a positive ANA titer. Neurologic examinations revealed asymmetric bilateral ptosis, weakness and fatigability in proximal muscles, and a severe reduction in the gag reflex. He was diagnosed with late-onset, seropositive MG. The treatment included pyridostigmine (60 mg, three times daily), intravenous immunoglobulin (25 g daily for 5 days), and oral prednisolone. There was no evidence of thymoma in the chest x-ray and CT scan without contrast. However, a CT scan with contrast was not performed due to the patient's unstable condition. A common autoimmune mechanism may underlie the unclear pathophysiology of MG and LP co-occurrence, with or without thymoma. Patients with MG, LP, or thymoma require close monitoring and assessment for other possible autoimmune diseases.

Survey of Medical Referral by Japanese Dentists for Patients With Hepatitis B, Hepatitis C, and Lichen Planus

OBJECTIVES

This study aimed to investigate the referral rates of oral lichen planus (OLP) and untreated hepatitis virus-infected patients by dentists to hepatologists.

MATERIALS AND METHODS

The study was conducted at three dental clinics in the Oita prefecture between November 2021 and June 2023. Two distinct groups of patients who visited the dentist for dental treatment were included: those with liver disease and concurrent hepatitis C virus (HCV) or hepatitis B virus (HBV) infection and those diagnosed with OLP. The rate of medical referrals to a hepatologist was investigated. Data on the number of patients, gender, age, diagnosis of liver disease, and referral practices were collected from the records submitted by each dental clinic. Information about the HCV and HBV infection status was collected through interviews with the dentists.

RESULTS

A total of 1,665 patients were included, of which 10 were HCV-infected, five were HBV-infected, and six were diagnosed with OLP. None of the 15 patients with liver disease were referred to a hepatologist by their dentists. Nine out of the 10 HCV-infected patients had achieved sustained virological response (SVR) after antiviral treatment. Of the six patients with OLP, one had a history of HBV infection, one had severe fatty liver, and the remaining four had normal livers; five of the OLP patients were referred to a hepatologist (83.3%).

CONCLUSION

A high referral rate from dentists to hepatologists was observed among the OLP patients. However, the study highlighted the difficulties in identifying hepatitis patients and establishing appropriate medical coordination in dental institutions.

Prevalence of oral lichen planus in patients with diabetes mellitus: A cross-sectional study

OBJECTIVES

Oral lichen planus, a chronic inflammatory immune disease, occurs in the oral mucosa. We aimed to assess the prevalence and possible influencing factors of oral lichen planus in patients with diabetes mellitus.

SUBJECTS AND METHODS

This cross-sectional study involved 525 patients with diabetes mellitus and 525 controls. We collected information on blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

RESULTS

Oral lichen planus was significantly more prevalent in the diabetes mellitus/type 2 diabetes mellitus group than in the controls (2.3%/2.2% vs. 0.6%, p = 0.019/0.022). There was no significant association between patients with diabetes mellitus with and those without oral lichen planus in age (p = 0.195), sex (p = 0.390), blood glucose level (p = 1), duration of diabetes (p = 0.638), diabetic complications (p = 1), treatment methods (p = 0.962), other systemic diseases (p = 0.891) and medication history (p = 0.848).

CONCLUSIONS

Diabetes mellitus was associated with oral lichen planus; there was a higher prevalence of oral lichen planus in patients with diabetes mellitus/type 2 diabetes mellitus than in those without diabetes. Oral lichen planus development in patients with diabetes mellitus was not significantly associated with age, sex, blood glucose level, duration of diabetes, diabetic complications, treatment methods, other systemic diseases and medication history.

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.

Risk factors for the development of oral precancerous lesions in a cohort of 293 oral lichen planus patients with or without chronic periodontitis in southern Taiwan

Background/purpose

Oral lichen planus (OLP) may contribute to the risk of chronic periodontitis, and no reports have shown whether OLP patients with periodontitis have a greater risk of oral precancerous lesions, Candida infection or other clinicopathological diseases. This study aimed to assess the risk factors for the development of oral precancerous lesions in a cohort of 293 OLP patients with or without chronic periodontitis in southern Taiwan.

Materials and methods

The current study recruited 293 OLP patients without preexisting periodontitis at a tertiary institution from 1995 to 2018. The patients were divided into two groups based on the presence or absence of periodontitis. The study compared various clinical and pathological characteristics between the two groups, and also estimated the odds ratio (OR) and the 10-year cumulative risk of chronic periodontitis in OLP patients using logistic regression models and Kaplan‒Meier analysis methods, respectively.

Results

After adjusting for age and gender, the significant contributors to oral precancerous lesions in OLP patients (P < 0.05) were periodontal disease (OR = 2.24) and the male gender (OR = 7.52). Betel nut consumption (OR = 2.61), smoking (OR = 2.46), and candidiasis infection (OR = 3.02) also showed significant associations. Older OLP patients had a lower lesion risk, while a longer OLP duration heightened the periodontal disease likelihood.

Conclusion

The present study demonstrated that coexisting periodontal disease increases the likelihood of developing precancerous lesions in patients with OLP. Periodontal management with oral hygiene care and quitting betel nut consumption and smoking can reduce the risk.

Oral Lichen Planus: An Update on Diagnosis and Management

Oral lichen planus (OLP) is a chronic inflammatory disease whose pathogenesis involves a T-cell mediated, epithelium-directed inflammation in response to unknown antigen(s). The disease evolves by intermittent flares and displays polymorphous clinical features (reticular, erosive, atrophic, plaque, papular, bullous, etc.). When present, symptoms vary depending on the clinical form and range from discomfort to severe pain. Topical superpotent corticosteroids constitute the first-line treatment of symptomatic flares, whereas a wide range of second/third-line treatments are available among topical calcineurin inhibitors, systemic corticosteroids, systemic retinoids, topical/systemic immunomodulators, etc. Follow-up of patients is necessary to detect transformation into squamous cell carcinoma, occurring in approximately 1% of patients.

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.

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.

Risk of Oral Squamous Cell Carcinoma in One Hundred Patients with Oral Lichen Planus: A Follow-Up Study of Umberto I University Hospital of Rome

This study aims to retrospectively assess the potential risk of malignant transformation in patients with diagnosed oral lichen planus (OLP) between 2015 and 2022, and to evaluate the influence of different risk factors. The department's database and medical records from 2015 to 2022 were searched for patients with a confirmed diagnosis of OLP based on both clinical and histological parameters. A total of 100 patients (59 females and 41 males) were found with a mean age of 64.03 years. In the considered period, the percentage of diagnosed OLP patients was 1.6%, while the percentage of diagnosed OLP patients with transformation to oral squamous cell carcinoma (OSCC) was 0.18%. A statistically significant difference was found with age (p = 0.038), tobacco status (p = 0.022), and radiotherapy (p = 0.041). The analysis revealed the presence of significant risk in ex-smokers (>20 pack-years), with an odds ratio (OR) of 10.0000 (95% confidence interval (95% CI) 1.5793-63.3186); in alcohol-drinker patients, with an OR of 4.0519 (95% CI 1.0182-16.1253); in ex-smoker and alcohol-drinker patients, with OR of 17.6250 (95% CI 2.2464-138.2808); and in patients who had undergone radiotherapy, with OR of 6.3000 (95% CI 1.2661-31.3484). The malignant transformation of oral lichen planus was slightly higher than thought, and the results revealed a possible association with age, tobacco and alcohol status, and history of radiotherapy. An elevated risk of malignant transformation was observed in heavy ex-smoker patients, alcohol-drinker patients, and alcohol-drinker patients with a history of smoking (ex-smokers). Persuading the patient to quit tobacco and alcohol consumption and periodic follow-ups are recommended in general, but particularly in the presence of these risk factors.

Comprehensive Insight into Lichen Planus Immunopathogenesis

Lichen planus is a chronic disease affecting the skin, appendages, and mucous membranes. A cutaneous lichen planus is a rare disease occurring in less than 1% of the general population, while oral illness is up to five times more prevalent; still, both forms equally impair the patient's quality of life. The etiology of lichen planus is not entirely understood. Yet, immune-mediated mechanisms have been recognized since environmental factors such as hepatitis virus infection, mechanical trauma, psychological stress, or microbiome changes can trigger the disease in genetically susceptible individuals. According to current understanding, lichen planus immunopathogenesis is caused by cell-mediated cytotoxicity, particularly cytotoxic T lymphocytes, whose activity is further influenced by Th1 and IL-23/Th-17 axis. However, other immunocytes and inflammatory pathways complement these mechanisms. This paper presents a comprehensive insight into the actual knowledge about lichen planus, with the causal genetic and environmental factors being discussed, the immunopathogenesis described, and the principal effectors of its inflammatory circuits identified.

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis C Virus Infection

Hepatitis C virus (HCV) is a significant cause of chronic liver diseases worldwide and is associated with negative consequences, including cirrhosis, hepatic decompensation, hepatocellular carcinoma, and increased risk of mortality. In addition to liver-related morbidities, HCV is also associated with several extrahepatic manifestations, including mixed cryoglobulinemia, diabetes mellitus, cardiocerebrovascular disease, lymphoma, and autoimmune diseases. These non-liver-related complications of HCV increase the complexity of this disease and can contribute to the economic burden, morbidity, quality of life, and mortality throughout the world. Therefore, understanding how this virus can contribute to each extrahepatic manifestation is worth investigating. Currently, the advancement of HCV treatment with the advent of direct-acting anti-viral agents (DAAs) has led to a high cure rate as a result of sustained virologic response and tremendously reduced the burden of extrahepatic complications. However, HCV-associated extrahepatic manifestations remain a relevant concern, and this review aims to give an updated highlight of the prevalence, risk factors, associated burdens, and treatment options for these conditions.

A review on interleukins (IL10 and IL17) as biomarkers for hepatitis C-associated oral lichen planus

Background

Hepatitis C virus is a viral infection associated with autoimmune disorders. This virus has hepatic and extrahepatic manifestations. One of the extrahepatic manifestations associated with the hepatitis C virus includes oral lichen planus. Oral lichen planus is an autoimmune disorder mainly affecting the tongue and buccal mucosa. It clinically represents grayish-white striae bilaterally on the buccal mucosa. The pathogenesis involves the progression of the hepatitis C virus, and oral lichen planus affects T lymphocytes. Specific proteins and cytokines activate these T lymphocytes, which act as biomarkers to detect certain diseases. Interleukin 10 is an anti-inflammatory cytokine, whereas interleukin 17 is a pro-inflammatory cytokine. These cytokines have a pathophysiological role and act as biomarkers for many diseases. Therefore, this review article aims to establish the role of interleukin 10 and interleukin 17 as biomarkers for hepatitis C-associated oral lichen planus.

Conclusion

Hepatitis C virus is an infectious disease that can lead to liver cirrhosis, and oral lichen planus is a premalignant lesion that can lead to oral carcinoma. As interleukin 10 lessens the immune pathologies and interleukin 17 mediates proinflammatory response, therefore, these biomarkers have a role in progression of these diseases.

Association of Hashimoto’s thyroiditis and anti-thyroid antibodies with oral lichen planus: A cross-sectional study

Hashimoto’s thyroiditis (HT) and its autoantibodies may be associated with oral lichen planus (OLP). In this cross-sectional study, we aimed to assess the relationship among HT, auto-anti-thyroid antibodies, and OLP in a Chinese population of 247 patients with oral lichen planus. Clinical manifestations of OLP were evaluated using the Thongprasom scoring system and clinical type. The diagnosis of HT was based on thyroid function, anti-thyroid peroxidase antibody (anti-TPOAb) and anti-thyroglobulin antibody (anti-TgAb) detection, and ultrasonography. The prevalence of HT in all patients with OLP was 39.68% (98/247); the prevalence in females with OLP was 46.24% (86/186), which was higher than that in males with OLP 19.67% (12/61) (P &lt; 0.01). The titers of the two HT autoantibodies in females with OLP were higher than those in males (P &lt; 0.01). The clinical manifestations of OLP, regardless of being evaluated using the Thongprasom system or clinical type, were not significantly associated with HT development or TPOAb (P = 0.864) or TgAb titers (P = 0.745). In this population-based southern Chinese cohort, the prevalence of HT in patients with OLP, particularly in female patients with OLP, was significantly higher than that in the general population. Female patients had higher HT autoantibody titers than male patients. However, the clinical manifestations of OLP were not significantly correlated with either HT development or auto-anti-thyroid antibody levels. The findings could help further elucidate the factors involved in the relationship between oral lichen planus and Hashimoto’s thyroiditis.

Lichen planus in Deutschland - Epidemiologie, Behandlung und Komorbidität. Eine retrospektive Krankenkassendatenanalyse

HINTERGRUND UND ZIELE

Lichen planus (LP) ist eine chronisch entzündliche Hauterkrankung, die eine große Belastung für die betroffenen Patienten darstellt. Es liegen jedoch nur wenige Daten zu dieser Erkrankung vor. Ziel dieser Studie ist es, das Wissen über die Epidemiologie und die Behandlungsmuster des LP anhand von Abrechnungsdaten deutscher Krankenkassen zu erweitern.

PATIENTEN UND METHODEN

Diese retrospektive Beobachtungsstudie nutzte die InGef-Forschungsdatenbank. Es wurden prävalente und inzidente LP-Patienten aus den Jahren 2015 und 2018 identifiziert. Für demografische Charakteristika, Behandlungsmuster und Komorbidität wurden deskriptive Statistiken berechnet.

ERGEBNISSE

Die Prävalenz des LP lag bei 95,9 und die Inzidenz bei 20,1 pro 100 000 Personen im Jahr 2018, was 79 605 prävalenten LP-Fällen in Deutschland entspricht. Die erste LP-Diagnose wurde in der Regel von einem Dermatologen oder Hausarzt gestellt. Drei Viertel der inzidenten und die Hälfte der prävalenten Patienten erhielten eine topische Therapie, meist ohne zusätzliche systemische Therapie. Die Komorbidität des LP stand im Einklang mit bereits bekannten Assoziationen.

SCHLUSSFOLGERUNGEN

Die verfügbaren Therapieoptionen sind nach wie vor begrenzt, was den ungedeckten Bedarf an sicheren und wirksamen systemischen Behandlungsmodalitäten unterstreicht. Der LP ist häufig mit klinisch relevanter systemischer Komorbidität verbunden. Zusammengenommen könnten diese Beobachtungen zu einem verbesserten Verständnis der Krankheitslast führen und das diagnostische Bewusstsein für diese Erkrankung unter Klinikern schärfen.

Lichen planus in Germany - epidemiology, treatment, and comorbidity. A retrospective claims data analysis

BACKGROUND AND OBJECTIVES

Lichen planus (LP) is a chronic inflammatory skin disease and is a major burden for affected patients. However, data on this condition are scarce. This study aims to expand the knowledge on the epidemiology and treatment patterns of LP using German health claims data.

PATIENTS AND METHODS

This retrospective observational study was based on the InGef research database. Prevalent and incident LP patients were identified in the years 2015 and 2018. Descriptive statistics were calculated for demographic characteristics, treatment patterns, and comorbidity.

RESULTS

The prevalence of LP was 95.9 and the incidence was 20.1 per 100,000 individuals in 2018, corresponding to 79,605 prevalent LP cases in Germany. The first LP diagnosis was generally documented by a dermatologist or a primary care physician. Three-quarters of the incident and half of the prevalent patients received topical therapy, mostly without further systemic therapy. Comorbidity in LP patients was consistent with previously known associations.

CONCLUSIONS

Available treatment options remain limited, underscoring the unmet need for safe and efficacious systemic treatment modalities. Lichen planus is frequently accompanied by clinically relevant systemic comorbidity. Taken together, these observations may improve our understanding of the burden of this disease and increase diagnostic awareness among clinicians.

Morphological Changes in the Oral Mucous Membrane in Viral Hepatitis C Patients: A Cross-Sectional Study

Background: The objective was to reveal the most typical changes in oral mucosa in HCV patients and compare them with those in HCV negative patients. Methods: The study involved 96 HCV patients and 100 patients without HCV who applied to a dental clinic. The content of cytokines IL-2, IL-4, IL-10 and ɤ-INF in the oral fluid was determined by ELISA. Buccal mucosa and gums biopsies passed histological examination. An immunohistochemical study of mucous membrane biopsies was performed using monoclonal mouse antibodies to CD3+ and CD20+. Results: The HCV patients group included 96 (63.5% males), and the non-HCV group included 100 subjects (62.0% males) with lesions of the oral mucous membrane. The lesions of lips and oral mucosa were more frequent in HCV than in the non-HCV group—e.g., erosion (13.5% vs. 1%), cracks in the mouth corners (42.7% vs. 0%), changes in the oral mucosa surface (89.6% vs. 3.0%), hemorrhages (78.1% vs. 0%), etc. The pro-inflammatory IL-2 level was higher and anti-inflammatory IL-4 level was lower in HCV patients compared with those in the non-HCV group. Conclusions: Morphological changes developed in the microvasculature both worsen the tissue trophism and accelerate the healing with differentiation into coarse-fibrous connective tissue. Immunohistochemical findings indicated a decrease in local humoral immune response.

Oral Microbiome Research on Oral Lichen Planus: Current Findings and Perspectives

Simple Summary

Oral lichen planus is a disease of the oral mucosa, which frequently affects women aged 40 years or older. Though the T cell-mediated immune response is involved in the development of oral lichen planus, attempts to identify a microorganism that causes the disease have been unsuccessful. Recent studies on the development of oral lichen planus are focusing on the role of the oral microbiome, which includes oral microbiota and their products, and the host environment. The role of the human microbiome in various diseases has been identified and regulating the microbiome is becoming important in personalized medicine. In this review, we summarized current findings on the role of the oral microbiome in the development of oral lichen planus. The homeostasis of the oral microbiome is disrupted in patients, and functional analysis of oral microbiota and oral mucosa implies that pathways involved in defense against bacterial infection and in the inflammatory response are activated in the oral lichen planus-associated oral microbiome. Though the lack of studies to date makes it difficult to conclude, further studies on the oral microbiome associated with the disease will enable a holistic understanding of the role of the oral microbiome in the development of oral lichen planus and developing a personalized therapy for the disease.

Abstract

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa with an unknown etiology. The role of oral microbes in the development of OLP has gained researchers’ interest. In this review, we summarized the findings of studies focused on the relationship between OLP and oral microbiome, which includes the composition of oral microbiota, molecules produced by oral microbiota or the host, and the oral environment of the host. According to the studies, the oral microbial community in OLP patients undergoes dysbiosis, and the microbial dysbiosis in OLP patients is more prominent in the buccal mucosa than in the saliva. However, no same microorganisms have been suggested to be associated with OLP in multiple investigations, implying that the functional aspects of the oral microbiota are more important in OLP development than the composition of the oral microbiota. According to studies on host factors that make up the oral environment, signal pathways involved in cellular processes, such as keratinization, inflammation, and T cell responses are triggered in OLP. Studies on the functional aspects of the oral microbiota, as well as interactions between the host and the oral microbiota, are still lacking, and more research is required.

The clinical impact of direct-acting antiviral treatment on patients affected by hepatitis C virus-related oral lichen planus: a cohort study

Objectives

Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous disease. Literature supports an association between OLP and Hepatitis C virus (HCV) infection. The current treatment for HCV infection with direct-acting antivirals (DAAs) is highly effective and safe. The aim of this study is to evaluate the clinical impact of viral eradication with DAAs in patients with HCV and OLP.

Materials and methods

For this cohort observational study, 18 patients with HCV and OLP were recruited; all patients received DAAs. Nineteen patients with OLP without HCV were recruited as controls. Both groups received an oral clinical examination, taking photographs of the oral mucosa, at three time points. Size and type of lesions, clinical and efficacy scores, were evaluated at each time point with ImageJ software. Changes were assessed by a general linear model repeated measures analysis. Kruskal–Wallis H and Mann–Whitney U tests were used to evaluate the differences between subgroups.

Results

All patients of the study group reached a sustained virological response. The study group showed a correlation between viral load and clinical status (p < 0.05), higher clinical scores at baseline (p = 0.001) and higher efficacy index than controls (p < 0.001), improving over time (p < 0.001); controls did not show significant changes (p = 0.196). One patient of the experimental group developed oral squamous cell carcinoma (OSCC) of the tongue during the DAAs treatment.

Conclusions

In this study, patients with HCV and OLP showed a worst clinical oral status than controls at baseline. However, treatment for virus eradication can improve the oral lichen planus clinical course.

Clinical relevance

HCV eradication can improve the clinical course of patients with HCV-related OLP.

French guidelines for the management of oral lichen planus (excluding pharmacological therapy)

INTRODUCTION

Oral lichen is a chronic inflammatory disease for which diagnostic management and follow-up are heterogeneous given the absence of specific guidelines in France. Our objective was to develop French multidisciplinary guidelines for the management of oral lichen.

MATERIALS AND METHODS

Working groups from the Groupe d'Etude de la Muqueuse Buccale (GEMUB) formulated a list of research questions and the corresponding recommendations according to the "formal consensus" method for developing practice guidelines. These recommendations were submitted to a group of experts and the degree of agreement for each recommendation was assessed by a scoring group.

RESULTS

Twenty-two research questions, divided into 3 themes (nosological classification and initial assessment, induced oral lichenoid lesions, and follow-up) resulted in 22 recommendations. Initial biopsy for histology is recommended in the absence of reticulated lesions. Biopsy for direct immunofluorescence is recommended for ulcerated, erosive, bullous types and for diffuse erythematous gingivitis. Management should include a periodontal and dental check-up, and investigation for extra-oral lesions. Hepatitis C testing is recommended only if risk factors are present. Definitions, triggering factors and the management of "induced oral lichenoid lesions" were clarified. Oral lichen must be monitored by a practitioner familiar with the disease at least once a year, using objective tools.

CONCLUSION

This formalised consensus of multidisciplinary experts provides clinical practice guidelines on the management and monitoring of oral lichen.

Immune mechanisms in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory disease of the oral mucosa that has been extensively researched over many years but as yet the mechanisms of pathogenesis are still not fully understood. Whilst the specific etiologic factors driving OLP remain ambiguous, evidence points to the development of a chronic, dysregulated immune response to OLP-mediating antigens presented by innate immune cells and oral keratinocytes leading to increased cytokine, chemokine and adhesion molecule expression. These molecules recruit T-cells and mast cells to the diseased site and orchestrate a complex interplay between cells that culminates in keratinocyte cell death, mucosal basement membrane destruction and long-term chronicity of the disease. The main lymphocytes involved are thought to be CD8+ cytotoxic and CD4+ Th1 polarised T-cells although recent evidence indicates the involvement of other Th subsets such as Th9, Th17 and Tregs, suggesting that a more complex immune cell relationship exists during the disease process. This review provides an overview of the immune mechanisms at play in OLP pathogenesis with particular emphasis on the role of the different Th subsets and how these recent discoveries may guide research toward identifying potential therapeutic targets.

Effect of hepatitis C antiviral therapy on oral lichen planus and hyposalivation in inmates

Background

Oral lichen planus (OLP) and hyposalivation have been reported as extrahepatic manifestations of hepatitis C virus (HCV) infection. Our study evaluated the effect of direct antiviral agents (DAAs) on OLP and hyposalivation in convicts with chronic hepatitis C, examining patients before, during and after the antiviral treatment period with direct acting antiviral agents (DAAs).

Methods

We screened 198 inmates for the presence of the HCV antibody. Patients found to be positive underwent a quantitative HCV-RNA test and HCV genotype typing, as well as an oral cavity examination using a scoring system for OLP (REU score) and the clinical oral dryness score (CODS). Subsequently, all patients underwent DAA therapy and a systematic physical examination of the oral cavity at 1, 3 and 6 months from the beginning of treatment.

Results

Fifty patients (25.25%) had a positive HCV-RNA test. At baseline, OLP was detected in 4 patients (8%), with a mean REU score of 10.13±4, and different degrees of hyposalivation were seen in 17 patients (34%), with a mean CODS score of 4.71±1.72. Six months after the start of DAA therapy, we observed resolution of OLP in 3 patients (75%) and improvement in the remaining subject with a significantly lower mean REU score (2±4). Hyposalivation disappeared in 5 patients, improved in 10, and remained unchanged in 2 patients with a significantly lower mean CODS score (0.06±0.24).

Conclusion

This study demonstrated the effectiveness of DAAs in the treatment of OLP and hyposalivation.

Lichen Planus

Lichen planus (LP) is a T cell-mediated disease affecting the stratified squamous epithelia of the skin and/or mucus membrane. Histologically, the disease is characterized by a lichenoid inflammatory infiltrate and vacuolar degeneration of the basal layer of the epidermis. LP has three major subtypes: Cutaneous, mucosal and appendageal LP. Rarely, it may affect the nails in the absence of skin and/or mucosal changes. LP may also be induced by several drugs, typically anti-hypertensive medication or be associated with infections, particularly viral hepatitis. The diagnosis is based on the clinical presentation and characteristic histological findings. Although the disease is often self-limiting, the intractable pruritus and painful mucosal erosions result in significant morbidity. The current first-line treatment are topical and/or systemic corticosteroids. In addition, immunosuppressants may be used as corticosteroid-sparing agents. These, however are often not sufficient to control disease. Janus kinase inhibitors and biologics (anti-IL-12/23, anti-IL17) have emerged as novel future treatment options. Thus, one may expect a dramatic change of the treatment landscape of LP in the near future.

A Review on Extrahepatic Manifestations of Chronic Hepatitis C Virus Infection and the Impact of Direct-Acting Antiviral Therapy

Extrahepatic manifestations are a feature of chronic hepatitis C virus (HCV) infection. In the course of chronic HCV infection, about 70% of patients have one or more extrahepatic manifestations. The latter are often the first and only clinical sign of infection. Experimental and clinical data support a causal association for many extrahepatic manifestations and HCV infection, which include mixed cryoglobulinemia, non-Hodgkin lymphomas (NHL), cardiovascular disease, insulin resistance, type 2 diabetes, neurological and psychiatric disease and other rheumatic diseases. All these extrahepatic conditions influence the morbidity, quality of life and mortality of HCV-infected patients. Currently, interferon-free therapeutic regimens with direct-acting antiviral agents (DAA) offer the possibility of treatment to almost the entire infected population, irrespective of stage of cirrhosis and associated serious comorbidities, always maintaining a high efficacy and tolerability. Several studies have shown a close association between HCV clearance by DAAs and an improvement or reduction in the risk of extrahepatic manifestations. Patients with HCV after a sustained virologic response (SVR) by DAA treatment have a lower risk than non-responders of developing cryoglobulinemic vasculitis and B-cell non-Hodgkin’s lymphomas. Furthermore, the SVR by DAA also reduces the risk of acute coronary syndrome, cardiovascular disease, insulin resistance and type 2 diabetes, and it improves atherosclerosis. HCV clearance by DAA also improves the quality of life and survival of patients with chronic HCV infection with associated extrahepatic diseases. Thus, DAAs should be initiated as early as possible in HCV patients with extrahepatic manifestations.

Association between hepatitis C virus infection and subsequent chronic inflammatory skin disease

Hepatitis C virus (HCV) infection is associated with several cutaneous manifestations, including lichen planus and psoriasis. However, its association with other chronic inflammatory skin diseases (CISD) remains largely unknown. The aim of this study was to investigate the association between HCV infection and CISD. Participants were recruited from the National Health Insurance Research Database in Taiwan. Altogether 23 509 patients with HCV infection and 94 036 matched controls were included to assess the risk of CISD. A Cox regression model was used for the analyses. Compared with controls, patients with HCV infection had an adjusted hazard ratio (aHR) of 6.34 (95% confidence interval [CI], 5.30-7.58) for CISD after adjustment for potential confounders. Regarding individual CISD, patients with HCV infection had a significantly increased risk of developing lichen planus, psoriasis, vitiligo, alopecia areata, and cutaneous lupus erythematosus. Interferon-based antiviral therapy (IFN-based AVT) was significantly associated with a decreased risk of CISD (aHR = 0.42; 95% CI, 0.28-0.64). Patients with HCV infection had a significantly increased risk of CISD, while IFN-based AVT was associated with a decreased risk. These findings suggest monitoring of CISD in patients with HCV infection.

Are oral lichen planus patients at high risk of hepatitis C? A case-control study

OBJECTIVE

To assess the correlation between oral lichen planus (OLP) and viral hepatitis C (HCV).

METHODS

This retrospective case-control study included a sample of OLP patients in a 3-year interval. The predictor variable was the presence of OLP (yes/no). The outcome variable was the diagnosis of HCV. Other study variables were grouped into demographic, anatomic, and clinical. Descriptive, bi- and multivariate statistics were computed with a significant level at P ≤ 0.05.

RESULTS

The sample was composed of 237 OLP patients (38.8% females) with a mean age of 59.9 ± 17.8 years (range, 17-96), and 948 age- and gender-matched control individuals. The significant higher frequency of HCV was identified in OLP patients (frequency: 19.8% vs. 2.1%; adjusted matched odds ratio [mOR_adj], 9.5; 95% confidence interval [95% CI], 5.98 to 15.91; P < 0.0001; Pearson's Phi coefficient [r_phi], 0.307). In the adjusted model, OLP with HCV was associated with 1) oro-cutaneous manifestations (mOR_adj, 17.58; 95% CI, 1.92 to 161.26; P = 0.0059; Bayesian posterior probability of positive test [W_p], 96%), 2) any intraoral forms other than reticular/plaque-liked forms (mOR_adj, 0.09; 95% CI, 0.04 to 0.18; P < 0.0001; W_p, 52%), and 3) poor response to topical corticosteroids (mOR_adj, 0.05; 95% CI, 0.02 to 0.16; P < 0.0001; W_p, 88%).

CONCLUSIONS

OLP, especially oro-cutaneous disease or steroid-refractory OLP, are associated with an increased frequency of HCV. Not only HCV screening in OLP patients, but oral examination in HCV patients, are both recommended as primary preventive measures.

Elevated mean platelet volume in oral lichen planus and increased blood urea nitrogen level in its red-form: an observational study

Background

This retrospective observational study aims to assess platelet count, mean platelet volume (MPV), blood biochemical tests for liver and kidney function in Chinese oral lichen planus (OLP) patients.

Methods

Eighty pathologically confirmed OLP patients and 51 healthy controls were enrolled. Data on full blood count and biochemical tests were obtained from the electronic medical record system of the hospital.

Results

MPV was elevated in OLP patients compared to controls (10.68 ± 0.97 fL versus 10.33 ± 0.89 fL, P = 0.042) while platelet count showed no difference between them. Red-form OLP group had increased blood urea nitrogen (BUN, 5.24 ± 1.15 mmol/L versus 4.69 ± 0.98 mmol/L, P = 0.036) than white-form OLP group. By contrast, there were no differences between those two groups in the other variables including MPV, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine. In terms of C-reactive protein (CRP), 92.5% of the OLP patients had a value of less than 3.48 mg/L. Besides, 75% of the OLP patients were overweight with body mass index (BMI) more than 25 kg/m².

Conclusions

These findings indicate MPV might play roles in inflammation in OLP. The red-form OLP might be associated with damage or reduction of kidney function.

The role of dentists in controlling hepatocellular carcinoma in Japan (Review)

In Japan, the method of treatment for hepatitis is well established due to the high rates of hepatitis C. However, the identification of patients with hepatitis who do not receive appropriate treatment poses a major problem. Some patients with this disease may need to consult with a dentist due to the development of extrahepatic manifestations, such as lichen planus, in the oral cavity. Alternatively, the dentist might discover patients with untreated hepatitis C and hepatitis B during routine dental examination. In such cases, the patient should be referred to a hepatologist for further examinations and treatment. Thus, dentists are required to act as 'gatekeepers of hepatitis'. Furthermore, Japanese dentists need to increase hepatitis B vaccine coverage for infection control. By acting as a 'care coordinator of hepatitis', the dentist will be able to contribute to the eradication of liver cancer in Japan, thereby eliminating the discrimination and prejudice against patients with hepatitis. Dentists need to have a deep understanding of liver disease from the viewpoints of both nosocomial infection control and treatment of oral diseases.

A Rare Case of Lichen Planus-Like Atopic Dermatitis Involving the Hands

Lichen planus-like atopic dermatitis clinically mimics lichen planus and can pose a diagnostic challenge. We report a case of a 55-year-old African American woman who developed intensely pruritic papules and plaques on bilateral hands. Histological examination demonstrated acute spongiotic dermatitis with lymphocyte exocytosis into the epidermis. Taken together, a diagnosis of lichen planus-like atopic dermatitis was made. This case serves to highlight that lichen planus-like atopic dermatitis can develop on hands and that it presents as spongiotic dermatitis with lymphocyte exocytosis into the epidermis. Correlating the clinical presentation with histopathological findings will assist in establishing the diagnosis and guiding appropriate management.

Evaluation of Dental Health in Terminally Ill Patients

Dental health plays an imperative role in the general health and well-being of an individual. Terminally ill patients due to a compromised immune response are susceptible to a wide array of oral complications, which may affect their ability to speak and chew, leading to malnutrition. The present study was conducted to evaluate dental health and various oral manifestations in terminally ill patients. One hundred twenty terminally ill patients hospitalized with diseases of the respiratory tract, gastrointestinal tract, circulatory system, liver, and endocrinal disorders were included in the study. The evaluation of oral manifestations and their prevalence was done by a single examiner. The oral health was evaluated according to symptoms exhibited by the patients and clinical presentation. Of the patients included in the study, 78 were male, and 42 were female. All the individuals were adults between 25 to 55 years of age. Out of 120 admitted terminally ill patients, 27 subjects had respiratory diseases, 17 had gastrointestinal disorders, 5 had disorders of the circulatory system, 39 had liver disorders, and 32 had endocrine disorders. A need for added comprehension is mandatory to link the inter-relationships between dentistry and medicine to further perk up the management of the overall health of patients, which will further reinforce the partnership between dental and medical communities.

The association between Epstein-Barr virus and oral lichen planus: A systematic review and meta-analysis

BACKGROUND

Oral lichen planus (OLP) is a relatively common inflammatory disease, with unclear etiology. A number of studies have linked Epstein-Barr virus (EBV) with OLP. The present systematic review and meta-analysis aimed to evaluate the available evidence regarding the potential association between EBV and OLP.

METHODS

Online databases (PubMed, Scopus, Web of Science, ProQuest, and Google Scholar) were searched from date of inception till May 2020. Studies were included if they met the following criteria: 1) observational studies that assessed the relationship between EBV and OLP, 2) the study comprised OLP patients and control subjects, 3) diagnosis of OLP was confirmed histopathologically, and 4) articles were in English. Studies without control groups, experimental studies, case reports, and reviews were excluded. The fixed-effects model was performed for meta-analyses using RevMan 5.3 software.

RESULTS

A total of 10 studies comprising 386 OLP cases and 304 controls were included. Of these, only 8 studies were eligible for the meta-analysis. The results of the quality assessment showed that only 2 studies were of high quality, while the remaining studies were of moderate quality. The results of the pooled eight studies revealed a significant positive association between EBV and OLP (OR = 4.41, 95% CI: [2.74, 7.11], P < .0001).

CONCLUSION

The results of the present systematic review suggest that EBV infection is statistically associated with increased risk of OLP. However, these results are preliminary, and high-quality, large-scale studies are warranted to further explore the potential role of EBV in the pathogenesis of OLP.

No detection of TSH or TSHR in oral lichen planus lesions in patients with or without hypothyroidism

Objective: An association between hypothyroidism (HT) and oral lichen planus (OLP) has been reported. However, the mechanisms that could explain this association remain unresolved. This study aimed to evaluate the expression of thyroid-stimulating hormone (TSH) and thyroid-stimulating hormone receptor (TSHR) in healthy oral mucosa and in OLP lesions of individuals with and without HT.Material and methods: Immunohistochemical expression of TSH and TSHR was studied in oral mucosal biopsies obtained from 14 OLP patients with HT, 14 OLP patients without HT and 10 healthy controls without oral mucosal lesions. Gene expression of TSHR was investigated by using three different PCR techniques in oral mucosal samples from 7 OLP patients with HT, 3 OLP patients without HT, 9 healthy controls and in cultured human oral epithelial cells. Gene expression of TSH was examined by employing 2 PCR techniques in oral mucosal samples from 2 OLP patients with HT, 2 OLP patients without HT and 4 healthy controls.Results: TSH and TSHR stainings were negative in the studied oral mucosal specimens. Gene quantification assays demonstrated negative gene expression of TSH and TSHR in clinical and in vitro samples.Conclusions: These results suggest that TSH and TSHR may not be commonly involved in the pathogenetic mechanism that could explain the association between OLP and hypothyroidism.

Generalized hypertrophic lichen planus: an atypical presentation of a characteristic disease

Lichen planus is a common chronic inflammatory condition that affects skin and mucous membranes. Management is often delayed because of patient embarrassment or misdiagnosis by the clinician. Early recognition and treatment is essential to reduce the morbidity of this condition. We present a 58-year-old woman diagnosed with generalized hypertrophic lichen planus, a rare event, reported to occur usually on lower extremities, but found to be generalized in our patient, requiring excision of symptomatic lesions. We suggest a multidisciplinary approach to allay the anxiety and symptoms of these patients and to improve the quality of life and clinical outcomes.

Oral Lichen Planus-Associated Oral Cavity Squamous Cell Carcinoma Is Associated With Improved Survival and Increased Risk of Recurrence

PURPOSE

We investigated the overall survival (OS), disease-specific survival (DSS), and disease-free survival among patients with oral lichen planus-associated oral cavity squamous cell carcinoma (OLP-OCSCC). The secondary objective was to assess the annual risk of tumor recurrence or second primary tumor (SPT).

MATERIALS AND METHODS

A comparative retrospective study was performed of patients with OLP-OCSCC presenting between June 2007 and December 2018 to the Department of Oral and Maxillofacial Surgery, Michigan Medicine (Ann Arbor, MI) and patients with OCSCC in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database (1973 to 2015).

RESULTS

A total of 87 patients with OLP-OCSCC met the inclusion criteria, and 55,165 patients with OCSCC from the SEER database were included. The proportion of women was greater in the OLP group than in the SEER group (56.3 vs 38.0%; P < .001). In the OLP group, 47.1% had no smoking history and 43.7% had no alcohol history. Most patients in the OLP group had presented with stage I disease (46.0%) compared with 31.7% in the SEER group (P = .004). Overall, the OS and DSS were significantly greater in the OLP group than in the SEER group at all points from 1 to 5 years (P ≤ .01). In the OLP group, 46 patients (52.9%) had at least 1 recurrence or SPT. At 10 years, the predicted mean number of recurrences was 1.93 per patient (95% confidence interval, 1.56 to 2.39).

CONCLUSIONS

OLP-OCSCC frequently affects women, nonsmokers, and nondrinkers and presents with localized disease at a high frequency. Patients with OLP-OCSCC have increased OS and DSS and a greater risk of tumor recurrence or SPT compared with OCSCC in the general population. Lifelong, frequent surveillance is recommended for patients with OLP-OCSCC owing to the risk of late recurrence. Future studies are needed to understand the pathophysiology of OLP-OCSCC.

The Frequency of Cutaneous Manifestations in Hepatitis C: A Cross-sectional Study in a Tertiary Care Hospital in Pakistan

Introduction

Even though the liver is the main targeted organ in hepatitis C, the manifestations of the disease are not limited to hepatic involvement. Other tissue types are often involved as well. Hepatitis C has dermatological and mucocutaneous manifestations.

Methods

This study was conducted from May 2016 to April 2017 in the gastroenterology unit of Ghulam Muhammad Mahar Medical College, Sukkur, Sindh, Pakistan. All participants with a clinical diagnosis of hepatitis C with cutaneous manifestations were included in the study after securing informed consent. Demographic data and detailed cutaneous examination results with full morphological descriptions were recorded in patient-completed questionnaires.

Results

Of the 212 participants, 141 (66.6%) were males and 71 (33.4%) were females. The mean age was 32 (±9) years (range: 17-58 years). The most common cutaneous manifestation was pruritus (33.96%), followed by lichen planus (LP) (23.5%).

Conclusion

Physicians should try to recognize extrahepatic manifestations of a hepatitis C infection as it may help in early diagnosis efforts. While managing hepatitis C, we recommend a multidisciplinary approach to tackle cutaneous and other extrahepatic manifestations.

Oral lichen planus and associated comorbidities: An approach to holistic health

Lichen planus (LP) is a chronic inflammatory disorder with involvement of skin, oral and genital mucosa, scalp, and nail appendages. Oral lichen planus (OLP) lesions demonstrate a number of morphologic presentations, persist for a long time with rare self-resolution, and undergo malignant changes. OLP has been associated with numerous systemic connotations such as metabolic syndrome, diabetes mellitus, hypertension, thyroid diseases, psychosomatic ailments, chronic liver disease, gastrointestinal diseases, and genetic susceptibility to cancer. The oral health physician should be aware of these systemic associations and should work in close connect with the primary healthcare physicians to rule out the predisposing factors for the associated comorbidities. This article aims to highlight the various systemic associations of OLP and warrants the screening of these ailments in OLP for prevention and effective management.

Mucocutaneous Diseases

Mucocutaneous diseases affecting the oral cavity are predominantly immune mediated or inflammatory. Three of the most common and clinically significant conditions are reviewed in this article: lichen planus, pemphigus vulgaris, and mucous membrane pemphigoid. Because oral manifestations may be the first or only manifestation of mucocutaneous diseases, oral health professionals play a critical role in the early diagnosis and multidisciplinary management of these conditions.

Lichen Planus Pemphigoides: From Lichenoid Inflammation to Autoantibody-Mediated Blistering

Lichen planus pemphigoides (LPP) is a very rare autoimmune sub-epidermal blistering disease associated with lichenoid skin changes. Initially thought to be a mere variant of more common inflammatory dermatoses, particularly Bullous Pemphigoid (BP) or Lichen Planus (LP), a growing body of evidence suggests that it is a disease entity in its own right. In common with a range of autoimmune blistering diseases, including BP, pemphigoid gestationis (PG), mucous membrane pemphigoid (MMP) and linear IgA dermatosis (LAD), a key feature of the disease is the development of autoantibodies against type XVII collagen (COL17). However, accurately establishing the diagnosis is dependent on a careful correlation between the clinical, histological and immunological features of the disease. Therefore, we present an up to date summary of the epidemiology and etiopathogenesis of LPP, before illustrating the predisposing and precipitating factors implicated in the development of the disease. In addition to a selective literature search, we compare reports of potential drug-induced cases of LPP with pharmacovigilance data available via OpenVigil. We subsequently outline the cardinal clinical features, important differential diagnoses and current treatment options. We conclude by demonstrating that an improved understanding of LPP may not only lead to the development of novel treatment strategies for the disease itself, but may also shed new light on the pathophysiology of more common and treatment-refractory autoimmune blistering diseases.

Ulcerated Lesions of the Oral Mucosa: Clinical and Histologic Review

Ulcerated lesions of the oral cavity have many underlying etiologic factors, most commonly infection, immune related, traumatic, or neoplastic. A detailed patient history is critical in assessing ulcerative oral lesions and should include a complete medical and medication history; whether an inciting or triggering trauma, condition, or medication can be identified; the length of time the lesion has been present; the frequency of episodes in recurrent cases; the presence or absence of pain; and the growth of the lesion over time. For multiple or recurrent lesions the presence or history of ulcers on the skin, genital areas, or eyes should be evaluated along with any accompanying systemic symptoms such as fever, arthritis, or other signs of underlying systemic disease. Biopsy may be indicated in many ulcerative lesions of the oral cavity although some are more suitable for clinical diagnosis. Neoplastic ulcerated lesions are notorious in the oral cavity for their ability to mimic benign ulcerative lesions, highlighting the essential nature of biopsy to establish a diagnosis in cases that are not clinically identifiable or do not respond as expected to treatment. Adjunctive tests may be required for final diagnosis of some ulcerated lesions especially autoimmune lesions. Laboratory tests or evaluation to rule out systemic disease may be also required for recurrent or severe ulcerations especially when accompanied by other symptoms. This discussion will describe the clinical and histopathologic characteristics of a variety of ulcerated lesions found in the oral cavity.

Potential pathogenic mechanisms involved in the association between lichen planus and hepatitis C virus infection

Lichen planus (LP) is an immune-mediated inflammatory disease that particularly affects the skin and mucous membranes. Its etiology remains elusive, however some trigger factors, including viral or bacterial antigens, drugs and metals, have been postulated. There is a higher prevalence of hepatitis C virus (HCV) infection among patients with LP, with some geographical variations. HCV is an enveloped RNA virus that belongs to the Flaviviridae family and in most instances causes chronic liver infections. It has been hypothesized that HCV may contribute to LP development, but the link between the two disorders is not fully understood. It is still debatable whether HCV leads to the occurrence of LP lesions directly by replication inside the infected cells or indirectly by activating immunological pathways. Molecular studies have revealed HCV RNA in specimens collected from patients with LP. The autoimmune theory was also suggested given that several studies have revealed viral replication and immune response activation associated with autoantibody synthesis. The aim of this review is to summarize the main potential mechanisms involved in the association between LP and HCV infection. Understanding the link between the two disorders may shed some light on the pathogenesis of LP, which is a challenging issue.

Lichen planus and diabetes mellitus: Systematic review and meta-analysis

OBJECTIVE

The aim of this study was to perform a systematic review and meta-analysis answering the following questions: (a) "What is the prevalence and risk of oral lichen planus among patients with diabetes mellitus?" and (b) "What is the prevalence and risk of diabetes mellitus among patients with oral lichen planus?".

MATERIAL AND METHODS

A bibliographic search was conducted in PubMed/Medline and Scopus database from 1966 to March 2018, using the following terms: "Lichen planus" AND "Diabetes mellitus" AND "Prevalence" AND "Oral mucosal lesions".

RESULTS

Twenty-two studies were included in this review. Twelve studies assessed the prevalence of diabetes mellitus among patients with lichen planus. The prevalence reported ranges from 1.6% to 37.7% with a relative risk of 2.432. Ten studies assessed the prevalence of lichen planus among patients with diabetes mellitus which showed a prevalence of lichen planus ranging from 0.5% to 6.1% with a relative risk of 1.4.

CONCLUSIONS

Contradictory results were found when analyzing the relationship between lichen planus and diabetes mellitus. Diverse factors should be considered when studying this association for a correct interpretation of results. Diabetes mellitus has high prevalence and morbidity, which is why new case-control studies are needed to further investigate this association.

Epstein-Barr Virus–Infected Plasma Cells Infiltrate Erosive Oral Lichen Planus

Epstein-Barr virus (EBV), in addition to its transforming properties, contributes to the pathogenesis of several inflammatory diseases. Here, we investigated its involvement in oral lichen planus (OLP), a common autoimmune-like disease of unknown etiopathogenesis that can display a malignant potential. EBV-infected cells (EBV+ cells) were sought in a large series of clinically representative OLPs ( n = 99) through in situ hybridization to detect small noncoding EBV-encoded RNAs. Overall, our results demonstrated that EBV was commonly found in OLP (74%), with significantly higher frequency (83%) in the erosive form than in the reticular/keratinized type mild form (58%). Strikingly, many erosive OLPs were massively infiltrated by large numbers of EBV+ cells, which could represent a large part of the inflammatory infiltrate. Moreover, the number of EBV+ cells in each OLP section significantly correlated with local inflammatory parameters (OLP activity, infiltrate depth, infiltrate density), suggesting a direct relationship between EBV infection and inflammatory status. Finally, we characterized the nature of the infiltrated EBV+ cells by performing detailed immunohistochemistry profiles ( n = 21). Surprisingly, nearly all EBV+ cells detected in OLP lesions were CD138+ plasma cells (PCs) and more rarely CD20+ B cells. The presence of EBV+ PCs in erosive OLP was associated with profound changes in cytokine expression profile; notably, the expression of key inflammatory factors, such as IL1-β and IL8, were specifically increased in OLP heavily infiltrated with EBV+ PCs. Moreover, electron microscopy–based experiments showed that EBV+ PCs actively produced EBV viral particles, suggesting possible amplification of EBV infection within the lesion. Our study thus brings conclusive evidence showing that OLP is commonly infiltrated with EBV+ PCs, adding a further puzzling element to OLP pathogenesis, given that PCs are now considered to be major regulatory immune cells involved in several autoimmune diseases (ClinicalTrials.gov NCT02276573).

Rate of malignant transformation of oral lichen planus: A systematic review

OBJECTIVE

The aim of this study was to systematically review the literature to determine: (a) the malignant transformation rate (TR) of oral lichen planus (OLP) and its risk factors; (b) whether or not oral lichenoid lesions (OLL) have a different malignant TR.

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science were used as search engines: only observational, full-length, English language studies were investigated. PRISMA protocol was used to evaluate and present results. PROSPERO registration code is CRD42016048529.

RESULTS

Among 7,429 records screened, only 21 were included in this review. Ninety-two of 6,559 patients developed oral squamous cell carcinoma, with an overall TR of 1.40% (1.37% for OLP and 2.43% for OLL), an annual TR of 0.20%. Female gender, red clinical forms, and tongue site seem to slightly increase the transformation risk.

CONCLUSIONS

This systematic review confirms that both OLP and OLL, the latter with a slightly higher TR, may be considered potentially malignant disorders and suggest that erosive type, female gender and tongue site should be considered as risk factors for OLP transformation. Major efforts should be done to establish strict clinical and histological criteria to diagnose OLP and to perform sounder methodological observational studies.

Efficacy of photodynamic therapy in the treatment of symptomatic oral lichen planus: A systematic review

BACKGROUND

The aim of this study was to systematically review the efficacy of photodynamic therapy (PDT) in the management of symptomatic oral lichen planus (OLP).

MATERIALS AND METHODS

PubMed/MEDLINE, Scopus, and ISI Web of knowledge were searched until July 2017, using the following keywords: OLP, erosive lichen planus, lichen planus, and PDT.

RESULTS

Five clinical studies were included. The risk of bias was considered high in 4 studies and moderate in 1 study. The efficacy of PDT was compared with topical corticosteroids in all included studies. Laser wavelengths, duration of irradiation, and power density ranged between 420-660 nm, 30 seconds to 10 minutes, and 10-500 mW/cm² , respectively. All studies reported PDT to be effective in the management of symptomatic OLP. Two studies reported PDT to be as effective as corticosteroids, 1 study reported a better efficacy of PDT compared to corticosteroids, whereas 2 studies found PDT to be inferior to corticosteroids.

CONCLUSIONS

The limited available evidence suggests that PDT is an effective treatment option for the management of OLP. However, due to the limited number of studies included in this review and heterogeneity among these studies, more well-designed clinical trials with adequate sample sizes are highly warranted.

Correlation Between Oral Lichen Planus and Thyroid Disease in China: A Case-Control Study

BACKGROUND

A possible relationship between oral lichen planus (OLP) and thyroid disease has received attention in recent years.

OBJECTIVE

This study aimed to evaluate the correlation between OLP and thyroid diseases in Chinese ethnic patients.

METHODS

192 OLP patients, 123 patients with oral lichenoid lesions (OLLs), and 162 controls were recruited in this case-control study. All participants received screening for thyroid function and underwent ultrasound. Sex and age of the patients in the three groups were matched. The prevalence of thyroid diseases in the subjects was analyzed. Using logistic regression, the odds ratio (OR) with 95% confidence intervals was appraised for associations between OLP, OLL, and different types of thyroid diseases [Hashimoto's thyroiditis (HT), hypothyroidism, and thyroid nodule].

RESULTS

The prevalence of thyroid diseases in the OLP group (72.4%) and OLL group (68.3%) was higher than the control group (49.4%) with statistical significance. The OR of HT was 3.16 (1.87-5.33) for OLP, 2.09 (1.18-3.70) for OLL, while the OR of thyroid nodule was 2.31 (1.30-4.09) for OLP.

CONCLUSION

Our study suggested a close relationship between OLP/OLL and HT and thyroid nodule in a Chinese population. The possible mechanism behind this association warrants further investigation.