Oral lichen planus and lichenoid reactions: etiopathogenesis, diagnosis, management and malignant transformation

Oral lichen planus: An update on pathogenesis and treatment

Oral lichen planus (OLP) is a chronic inflammatory disease that affects the mucus membrane of the oral cavity. It is a T-cell mediated autoimmune disease in which the cytotoxic CD8+ T cells trigger apoptosis of the basal cells of the oral epithelium. Several antigen-specific and nonspecific inflammatory mechanisms have been put forward to explain the accumulation and homing of CD8+ T cells subepithelially and the subsequent keratinocyte apoptosis. A wide spectrum of treatment modalities is available, from topical corticosteroids to laser ablation of the lesion. In this review, we discuss the various concepts in the pathogenesis and current treatment modalities of OLP.

Oral conditions associated with hepatitis C virus infection

Hepatitis C virus (HCV) infection in more than 170 million chronically infected patients with no developed preventive vaccine is a globally important issue. In addition to expected hepatic manifestations, a number of extrahepatic manifestations, such as mixed cryoglobulinemia, glomerulonephritis, polyarteritis nodosa, rashes, renal disease, neuropathy, and lymphoma, have been reported following HCV infection, which are believed to be influenced by the virus or the host immune response. HCV combination therapy with pegylated interferon and ribavirin might be associated with side effects as well. The association of HCV with special oral conditions has also been reported recurrently; the mechanism of most of which remains unclear. This article reviews the association of HCV infection with some of the oral conditions such as oral health, Sjogren's syndrome, lichen planus and oral cancer.

Salivary IgA and IgG in oral lichen planus and oral lichenoid reactions diseases

BACKGROUND

The objective of this study was to assess the level of salivary IgA and IgG in oral lichen planus (OLP) and oral lichenoid reactions (OLR) patients as diagnostic factors to the differential diagnosis of OLP, OLR diseases.

MATERIALS AND METHODS

Saliva sample were obtained from 50 OLP, 50 OLR patients and 50 healthy subjects between April 2010 and October 2011. The clinical relevant data taken into account were: Demographical data, previous medication, and level of salivary IgA and IgG. Each sample was assessed to determine the level of salivary IgA by ELISA test and salivary IgG by radial immune diffusion.

RESULTS

The mean of salivary IgA and IgG in patients were 119.01 ± 114.18 mic/ml and 3.25 ± 1.81 mic/ml, respectively. There were no significant differences for salivary IgA and IgG between OLP and OLR, but the mean of salivary IgA and IgG in OLP and OLR patients were significantly more than normal group (P-value < 0.05). The cut-off value was set at >72 mic/ml for salivary IgA in both OLP and OLR groups and set at >3.7 mic/ml for salivary IgG. On comparing the AUCs, there was no significant difference between AUCs for IgA (0.715 ± 0.05vs. 0.69 ± 0.5, for OLP and OLR patients, respectively,P-value = 0.7) and IgG (0.681 ± 0.05 vs. 0.548 ± 0.06, for OLP and OLR patients, respectively, P-value = 0.1).

CONCLUSIONS

Our results showed that the level of salivary IgA and IgG in OLP and OLR patients is higher than healthy controls, but they cannot be used as diagnostic factors to the differential diagnosis of OLP and OLR.

Role of mast cells in pathogenesis of oral lichen planus

Recent attention has been directed toward the role of mast cells in the pathogenesis of oral lichen planus. Mast cells are responsible for trafficking inflammatory cells into the connective tissue that in turn helps in progression and maintenance of chronicity of oral lichen planus (OLP). OLP is a T-cell-mediated chronic inflammatory oral mucosal disease of unknown etiology, and lesions contain few B-cells or plasma cells and minimal deposits of immunoglobulin or complement. Hence, OLP is ideally positioned for the study of human T-cell-mediated inflammation and autoimmunity. This study was done to evaluate the mast cell count using toluidine blue stain in OLP and compares it with oral lichenoid reaction (OLR), and to propose the possible role of mast cells in the pathogenesis of OLP and OLR. Ten cases each of OLP and OLR and five cases of normal buccal mucosa were taken from the archives of Department of Oral Pathology. The samples were stained with toluidine blue using standard toluidine blue method by Wolman 1971. An increase in mast cell count was observed in OLP and OLR in comparison to normal oral mucosa. However, no significant differences in mast cell count were noted between OLP and OLR.

FoxP3(+) T regulatory cells in oral lichen planus and its correlation with the distinct clinical appearance of the lesions

The aim of this study was to evaluate the presence of FoxP3(+) cells in oral lichen planus (OLP) and to correlate the findings with clinical and histopathological features of these lesions. The sample consisted of 32 cases of OLP (17 reticular and 15 erosive cases) and 10 cases of inflammatory fibrous hyperplasia (IFH). Clinical examination, histopathological and histomorphometric analysis, and immunohistochemistry (anti-FoxP3 antibody) were performed. Cells were counted in juxtaepithelial and intraepithelial regions of the lesions, and the results are expressed as the mean and range. Most erosive lesions were keratinized and exhibited epithelial atrophy, whereas most reticular lesions were hyperkeratinized. Mean epithelial thickness and mean density of the inflammatory infiltrate were higher in reticular lesions than in erosive OLP. Juxtaepithelial FoxP3(+) cells were slightly more frequent in erosive lesions (mean: 1.7 and range: 0-9.4) than in reticular lesions (mean: 1.5 and range: 0-8.3). There was a significant difference in the frequency of these cells between OLP (mean: 1.6 and range: 0-9.4) and IFH (mean: 0.5 and range: 0-1.4) (P < 0.05). The number of intraepithelial FoxP3(+) cells was higher in reticular OLP and IFH when compared with erosive lesions. The larger number of juxtaepithelial FoxP3(+) cells in OLP compared to IFH might be related to the distinct etiopathogenesis of these lesions. High disease activity or action of the oral microbiota may explain the slightly higher frequency of FoxP3(+) cells in erosive lesions.

Mast cells distribution and variations in epithelium thickness and basement membrane in oral lichen planus lesion and oral lichenoid reaction

Background:

Oral lichen planus (OLP) is a chronic mucocutaneous lesion with unknown etiology. Oral lichenoid lesions (OLL) comprise a family of lesions with different etiologies. Both lesions have similar clinical and histopathologic characteristics although their management is different. Differential diagnosis between OLP and OLL has always been a major challenge.

Materials and Methods:

In this prospective analytical study, the role of mast cells in pathogenesis of these lesions was investigated by evaluation of 52 patients with clinical and histopathological diagnosis of OLP (26 cases) and OLL (26 cases) based on WHO criteria, and by applying a more accessible staining methods, Hematoxylin and Eosin, toluidine blue (histochemistry) and Periodic Acid Schiff staining. In order to distinguish these two lesions, number of mast cells and thickness of epithelium and basement membrane were measured using light microscopy. Data were analyzed by SPSS software using t-test method (P<0.001).

Results:

No significant difference was observed between the total numbers of mast cells of two groups (P=0.148), but a statistically significant difference was detected between degranulated mast cells in two groups (P<0.001). A significant difference was also observed between the thickness of epithelium in two groups (P<0.001), although no difference was seen between basement membrane thickness in these lesions.

Conclusion:

Number of degranulated mast cells in reticular layer of corium in lichenoid lesions was more than that of OLP. This implies that despite the increase in number of these cells, in both groups of diseases, the role of these cells has not been the same in pathogenesis of the diseases. Moreover, the epithelium thickness was lower in lesions of OLP compared to lesions of oral lichenoid, so this parameter may be a useful criterion together with other histopathological and clinical finding to discriminate these lesions. However, discrepancy of basement membrane thickness can not be a reliable criterion. Finally we suggest more accessible staining methods which are reliable for differentiation of these two lesions.

Degranulated mast cells and TNF-α in oral lichen planus and oral lichenoid reactions diseases

Background:

The objective of this study was to assess mast cells and TNF-α in oral lichen planus (OLP) and oral lichenoid reactions (OLR) patients as diagnostic marker to the differential diagnosis of OLP and OLR diseases.

Materials and Methods:

In this cross-sectional study, samples were obtained from 30 OLP and 30 OLR patients, between June 2010 and March 2011 in Dental clinic of the University of Isfahan, Iran. Mast cells in the reticular layer of the lamina propria for samples were evaluated using toluidine blue method and immunohistochemical technique. The clinical relevant data taken into account were: demographical data, total number and degranulated mast cells, ratio of degranulated mast cells and TNF-α positive degranulated mast cells.

Results:

In OLP and OLR, the total mast cells were 21.2 ± 7.9 and 20.3 ± 6.8, degranulated mast cells were 15.5 ± 6.9 and 19.2 ± 6.9, ratio of degranulated mast cells to total mast cells were 0.716 ± 0.067 and 0.946 ± 0.081, and TNF-α positive degranulated mast cells were 13.6 ± 6.3 and 17.1 ± 6.04, respectively. There was no significant difference for the total mast cells. But degranulated mast cells, ratio of degranulated mast cells and TNF-α positive degranulated mast cells in OLR were significantly higher than OLP patients.

Conclusions:

Our results showed that the degranulated mast cells, ratio of degranulated mast cells and TNF-α in OLR was significantly more than OLP patients and these may be able to be used as diagnostic markers to the differential diagnosis of OLP and OLR.

Oral lichen planus - Review on etiopathogenesis

Oral lichen planus (OLP) is a chronic mucocutaneous disease of uncertain etiopathogenesis. Several factors including stress, genetics, systemic diseases, viruses, dental restorative materials and drugs have been implicated as causative agents. The disease seems to be mediated by an antigen specific mechanism, activating cytotoxic T cells, and non specific mechanisms like mast cell degranulation and matrix metalloproteinase activation. Further clarity on the pathogenesis will aid in modifying therapeutic interventions, thus significantly reducing the morbidity of OLP patients.

Prevalence of hepatitis C and hepatitis B virus infection(s) in patients with oral lichen planus

AIM

The aim of this study was to determine the prevalence of hepatitis B virus and hepatitis C virus (HCV) infections in patients with oral lichen planus (OLP) and to compare it with that of general population.

MATERIALS AND METHODS

A total of 60 patients were included in the study. Patients were selected from the outpatient department of Rama Dental College Research Centre, Kanpur, Uttar Pradesh. Thirty patients with OLP were included in Group 1. Thirty age- and sex-matched healthy patients with no history of oral or skin lesions were included in Group 2. Detailed case history, biopsy (the most representative site of the lesion is chosen for specimen), detection of hepatitis B surface antigen (HBsAg), and detection of anti-HCV antibody were carried out.

RESULTS

The serum of the entire study sample (Group 1 and Group 2) was tested for both hepatitis C antibodies and HBsAgs with the enzyme-linked immunosorbent assay (ELISA) test (using the third generation kit). It was found negative for both HBsAgs and hepatitis C antibodies.

CONCLUSION

In the present study, all the samples including OLP patients and healthy patients were seronegative for both hepatitis B (HBsAg) and hepatitis C (HCV antibody).

Oral lichenoid lesions associated with amalgam restorations: a prospective pilot study addressing the adult population of the Basque Country

Oral lichenoid lesions (OLLs) are linked to a heterogeneous group of pathologies involving the oral mucosa that cannot be distinguished from the oral lichen planus excepting the fact that direct causal factors such as silver amalgam restorations (SARs) can be allocated to them. Purpose: To analyze the prevalence of mucosal lesions associated with SAR in a group of SAR carrying patients in the Basque Country. Study Design: A clinical prospective study was carried out on 100 adult patients over 30 years of age at the UPV/EHU Clinical Odontology Service whose rear teeth had at least one SAR. Patients were identified and mucosal lesions and amalgam restorations were characterized. Patch tests were performed on patients with lesions and amalgams were replaced with composite material. A statistical and comparative analysis was performed with the resulting data. Results: OLLs were found in 7 patients whose predominant lesion was bilateral, asymmetrical and asymptomatic white papule-macule. Lesions were related to old and corroded SARs. Patch testing was positive in two cases. SAR substitution produced an improvement in 5 cases. Conclusions: The presence of lichenoid lesions associated with SARs is infrequent in our environment and is preferentially related to old and corroded restorations.

Key words:Oral mucosa, lichenoid lesions, restoration, silver amalgam, patch test.

Comparison of periodontal status in gingival oral lichen planus patients and healthy subjects

Background and Objective. Oral lichen planus (OLP) is a common chronic mucocutaneous disease. OLP can occur in different oral sites such as gingiva. The purpose of study was to evaluate the periodontal status of OLP patients with desquamative gingivitis (DG) and compare it with that of healthy control. Methods. This study was case-control. 32 patients with gingival OLP as a case group and 32 healthy subjects as a control group were selected. The periodontal status of all subjects including plaque index (PI), bleeding on probing (BOP), and clinical attachment level (CAL) was evaluated in both groups. Finally data were analyzed by t-test. Results. The mean values of periodontal parameters were observed to be higher in case group compared with control group, and this was significant (P < 0.05). Conclusion. Our results showed that periodontal status is worse in gingival OLP if compared with healthy controls.

Clinical and histologic healing of lichenoid oral lesions following amalgam removal: a prospective study

OBJECTIVE

This study aimed to see whether clinical healing after amalgam removal corresponds to histologic healing, i.e., a complete disappearance of any histologic sign of lichenoid lesion.

STUDY DESIGN

The study evaluated 64 patients with lichenoid lesions and at least one amalgam filling.

RESULTS

After amalgam removal, complete clinical healing was obtained in 14 patients (22%) and was significantly related to lesion topography (χ(2) 4.7; P < .05) and positive patch test (χ(2) 6.3; P < .01). Complete histologic healing was obtained in only 7 cases (50% of clinically healed patients), and was significantly related to the combination of positive patch test and strict contact with amalgams (Fisher's exact test P < .01).

CONCLUSIONS

Contact with amalgams and positive patch testing are good but not absolute indicators of the beneficial effect of amalgam replacement. In addition, complete clinical healing does not necessarily mean a disappearance of the histologic characteristics of OLL/OLP lesions.

The dynamics of oral lichen planus: a retrospective clinicopathological study

To evaluate disease dynamics, treatment results, and frequency of malignant transformation. Ten-year single center retrospective study. The study included 171 patients, 28-99 years old. Follow-up was 1-16 years. 49.5% exhibited changes in clinical presentation, with 19% yearly increase of probability for type shift. Index of extent (number of oral locations) showed a mean 40% decrease and 94.1% reported improvement. There were significant differences between treated and untreated patients (P=0.012). Patients with or without systemic diseases had identical treatment requirements for oral lesions. The prevalence of SCC was 5.8%. Oral lichen planus constantly changes presentation and extent of involvement. The effect of systemic diseases was insignificant in the present study. There is a clear value for treatment to reduce the extent of lesions. The results indicate that all clinical forms of the disease need to be equally followed since the clinical presentation typically changes over time, while malignant transformation can occur in all forms.

Oral lichen planus (OLP): clinical and complementary diagnosis

Lichen planus is a common disorder of the stratified squamous epithelium that affects oral and genital mucous membranes, skin, nails, and scalp. Oral Lichen Planus (OLP) affects middle-aged women and shows distribution patterns and characteristics such as white striations, white plaques or papules, erythema, blisters and erosions, and may be associated with medication and/or dental materials used by the patient. The clinical diagnosis can only be made if the disease presents classical patterns such as concomitant lesions in the oral mucosa and skin. The laboratory diagnosis is histopathologically characterized by the presence of projections of the epithelium in the form of sawtooth and Civatte bodies and allows the exclusion of dysplasia and malignancy. Direct immunofluorescence is used when there is suspicion of other diseases, such as pemphigus and pemphigoid. OLP is treated with anti-inflammatory agents, particularly topical corticosteroids; new agents and techniques have proved effective. The malignant transformation of OLP and its exact incidence remain controversial. This work aims at presenting, through literature review, the etiopathogenesis, clinical diagnosis, laboratory tests, and complications of OLP.

Cigarette smoking induces overexpression of c-Met receptor in microvessels of oral lichen planus

INTRODUCTION

Cigarette smoking is related to many pathological conditions; however, chemical substances affect the oral cavity first, so it is important to consider its influence on oral mucosa and oral potentially pre-malignant lesions. The aim of this study was to investigate the effect of smoking on microvessel density in oral lichen planus. Special emphasis was placed on examining the relationship between the expression of c-Met receptor in blood vessels and smoking habits.

MATERIAL AND METHODS

This study included 34 patients with oral lichen planus diagnosed clinically and verified by histopathological examination and 12 healthy individuals as controls. Biopsy of oral mucosa was performed and specimens were examined for immunohistochemical CD34 and c-Met receptor expression. The microvessel density was established by evaluation of the five most vascular areas within a section.

RESULTS

Compared to normal oral mucosa, in lichen planus patients, significantly higher blood vessel density and c-Met expression were noted. Irregular distribution of microvessels was typical for oral lichen planus. Also, microvessel density was higher in cigarette smoking patients' tissues than in non-smoker specimens. Furthermore, the association of c-Met expression with smoking habit was statistically significant.

CONCLUSIONS

Cigarette smoking habit has a direct impact on the oral lichen planus course; therefore, close follow-up of these patients is mandatory.

Oral lichen planus and malignant transformation: a longitudinal cohort study

OBJECTIVE

Oral lichen planus (OLP) is associated with risk for developing oral squamous cell carcinoma (OSCC). We performed a 7-year prospective study to assess the incidence of malignant transformation of OLP among adults.

STUDY DESIGN

Three hundred twenty-seven OLP patients, 229 women (70.0%) and 98 men (30.0%), were observed during the follow-up period.

RESULTS

During a mean follow-up of 81.7 months, 8 of 327 patients developed an OSCC in OLP areas (0.36%/y), yielding the high overall standardized incidence ratio of 17.7 (95% confidence interval [CI] 8.8-35.3). The standardized incidence ratio for OSCC was significantly higher in women [27.0 (95% CI 11.2-64.8)] than in men [11.2 (95% CI 3.6-34.9)]. Six OSCCs were well differentiated (75%) and 2 moderately differentiated (25%). Three subjects (37.5%) developed recurrences within 2 years (mean 16.1 ± 3.5 months). Disease-free survival rate after 69.8 months was 97.3%.

CONCLUSIONS

OLP was associated with a significant increase in the risk for OSCC. Close surveillance may help to reduce the morbidity of OSCC arising from OLP at 24 months.

Perforin and granzyme B involvement in oral lesions of lichen planus and chronic GVHD

BACKGROUND

Oral lesions of lichen planus and chronic graft-vs.-host disease (cGVHD) have similar clinical and histological features, but distinct etiology. Apoptosis induced by cytotoxic T lymphocyte has been proposed as a mechanism of keratinocytes death. Cytotoxicity can be mediated by granules containing granzyme B and perforin. Since common features can reflect similarities in immunological mechanisms, we studied the role of those molecules in both diseases.

METHODS

We analyzed 29 cases of oral lichen planus and 27 of oral cGVHD. The sections were studied on H&E, perforin and granzyme B staining.

RESULTS

The total means (epithelium plus connective tissue number) of the granzyme B- and perforin-positive cells were significantly higher in cGVHD than in oral lichen planus lesions (P<0.05). Also, it was found that the higher the number of perforin+ cells, the higher the number of granzyme-B+ cells in the epithelium and in the connective tissue for both groups (P < 0.05). In oral lichen planus, the number of single apoptotic bodies had a positive correlation with connective tissue granzyme immunostaining and a negative correlation with perforin (P<0.01). On the contrary, in oral cGVHD, the number of apoptotic body clusters presented a positive correlation with connective tissue perforin (P<0.01).

CONCLUSIONS

Our findings indicate that apoptosis in oral lichen planus seems to be correlated with granzyme B release, while in oral cGVHD, perforin seems to be more important. Although these diseases present clinical and histological similarities, subtle differences seem to exist in their pathogenetic mechanisms.

Topical immunomodulators for management of oral mucosal conditions, a systematic review; part I: calcineurin inhibitors

IMPORTANCE OF THE FIELD

Topical immunomodulators have been used for the management of oral mucosal diseases. Topical immunomodulating preparations may have utility in local management of oral disease which is resistant to topical steroids and oral findings of an immunologic-mediated systemic disease with primary or persisting, oral mucosal involvement.

AREAS COVERED IN THIS REVIEW

This paper is the first part of a systematic review of topical immunomodulators for the management of various oral indications focused on calcineurin inhibitors. The literature search revealed that data are available for cyclosporine, tacrolimus and pimecrolimus. In addition to the review of scientific evidence, this paper presents the potential market, the mechanism of action, the competitive environment and future development options.

WHAT THE READER WILL GAIN

The reader will find weighted conclusions for the topical use of the calcineurin inhibitors in the management of oral diseases.

TAKE HOME MESSAGE

Topical calcineurin inhibitors may be useful as a second-line treatment in several oral diseases, particularly oral lichen planus.

Levels of salivary IFN-gamma, TNF-alfa, and TNF receptor-2 as prognostic markers in (erosive) oral lichen planus

To explore the feasibility of detecting salivary levels of IFN-γ, TNF-α, and sTNFR-2 from erosive oral lichen planus (ELP) patients for clinical application, 20 ELP patients were enrolled in the study as were 20 age-sex-matched controls. From all subjects, saliva level of the tested biomarkers was determined by ELISA. Salivary profiles were assessed in ELP patients by ELISA after being treated with prednisone. A significantly higher level of IFN-γ (P ≤ .01), TNF-α (P ≤ .0001), and sTNFR-2 (P ≤ .01) was detected in ELP patients before treatment than in controls. Following treatment, the salivary levels of IFN-γ (P ≤ .01), TNF-α (P ≤ .05), and sTNFR-2 (P ≤ .01) decreased significantly when compared to their pretreatment levels. This study demonstrated that salivary IFN-γ, TNF-α, and sTNFR-2 can be detectable in ELP patients and decreased significantly after treatment with prednisone, which may reveal the possibility of using these disease-related biomarkers in diagnosis and monitoring.

Common oral mucosal diseases, systemic inflammation, and cardiovascular diseases in a large cross-sectional US survey

BACKGROUND

Inflammation of the gingivae (periodontitis) has been associated with raised serum biomarkers of inflammation, sub-clinical markers of atherosclerosis, and increased risk of and/or mortality from cardiovascular disease (CVD). There remain little information regarding the association between other common oral inflammatory disease, systemic inflammation, and CVD. The objective of the study was to assess the association between common oral mucosal diseases, circulating markers of inflammation, and increased prevalence of CVD in a cross-sectional survey of a nationally representative sample of the noninstitutionalized civilians in the United States.

METHODS

Data for this study are from 17,223 men and women aged ≥ 17 years who received oral examination as part of the Third National Health and Nutrition Examination Survey. The primary and secondary outcome measures were the association of oral mucosal diseases with raised serum levels of C-reactive protein/fibrinogen and increased prevalence of CVD, respectively. Adjustment for common confounding factors was performed.

RESULTS

Having oral mucosal disease was associated with systemic inflammation (serum levels of C-reactive protein ≥ 10 mg/dL) (odds ratio 1.41, 95% CI 1.02-1.94). Individuals with oral mucosal disease were 1.36 times (95% CI 1.02-1.80) more likely to have history of myocardial infarction and 1.33 times (95% CI 1.03-1.71) more likely to report angina than unaffected individuals. All associations were independent of common confounding factors.

CONCLUSIONS

This is the first study to suggest that common oral mucosal diseases are independently associated with raised markers of systemic inflammation and history of CVD.

Oral mucosal diseases: the inflammatory dermatoses

The oral inflammatory dermatoses is a term used to describe a number of predominantly immune-mediated disorders: lichen planus (LP), erythema multiforme (EM), the vesiculobullous diseases pemphigoid (MMP), pemphigus (PV) and epidermolysis bullosa acquisita (EBA). These conditions are characterized by frequent involvement of the oral mucosa and often associated with extraoral manifestations, particularly of the skin, but can involve the eyes, both the conjunctiva and sclera, the nasal and pharyngeal mucosa, as well as the genitals. Given their frequent, and sometimes initial involvement of the oral mucosa, oral health professionals need to be both familiar with the clinical features and presentations of these conditions, and appreciate their critical role in management. This paper reviews the clinical features and presentation of the oral dermatoses, provides guidance as to the appropriate investigations needed to differentiate and correctly diagnose these conditions, details the aetio-pathology of these diseases and discusses their management.

Pathogenesis of oral lichen planus--a review

Oral lichen planus (OLP) is a T-cell-mediated chronic inflammatory oral mucosal disease of unknown etiology. OLP presents as white striations, white papules, white plaques, erythema, erosions, or blisters affecting predominantly the buccal mucosa, tongue and gingiva. Both antigen-specific and non-specific mechanisms are hypothesized to be involved in the pathogenesis of oral lichen planus (OLP). Antigen-specific mechanisms in OLP include antigen presentation by basal keratinocytes and antigen-specific keratinocyte killing by CD8(+) cytotoxic T cells. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase activation in OLP lesions. These mechanisms may combine to cause T cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T cell migration and keratinocyte apoptosis in OLP. The various hypotheses proposed for pathogenesis of oral lichen planus are discussed in this review.

A Case of Lichen Ruber Planus in a Patient with Familial Multiple Sclerosis

Multiple sclerosis and lichen ruber planus are clinically and histologically distinct complex disorders of putative autoimmune aetiology that are fairly commonly observed in isolation but rarely found in combination. Only two previous reports have described lichen skin disorders in association with multiple sclerosis. The present report describes the case of a 51-year old Caucasian woman exhibiting both familial multiple sclerosis and lichen ruber planus. This combination may have occurred by chance or it might imply that these disorders share common mechanisms in their pathogenesis.

White oral lesions, actinic cheilitis, and leukoplakia: confusions in terminology and definition: facts and controversies

Many diseases affecting the cutaneous tissues may incur observable changes to the mucosal tissues of the oral cavity. As a consequence, the dermatologist should always assess the oral mucosal tissues of their patients as a matter of routine. Equivocal lesions should be referred to a dentist for further assessment. Although most encountered white oral lesions are innocuous, some potentially serious conditions may mimic an innocuous white lesion. As examples, oral lichen planus may cause significant patient discomfort and is associated with some degree of increased malignant risk, whereas actinic cheilitis and leukoplakia have a confirmed association with an increased malignant risk. This contribution reviews the characteristics and management strategies for some of the more common white oral lesions that the dermatologist may observe in clinical practice.

Derivation and validation of a risk-factor model for detection of oral potentially malignant disorders in populations with high prevalence

BACKGROUND

Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.

METHODS

A community-based case-control study (n=1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.

RESULTS

A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).

CONCLUSION

This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability.

Cytochrome P450 2D6 polymorphism and drug utilization in patients with oral lichen planus

OBJECTIVE

Oral lichen planus (OLP) is one of the commonest diseases of the oral mucosa. The etiology of the disease is unknown. Our goal was to determine frequencies of functionally important alleles which determine the metabolic rate (phenotype) of individuals with OLP and to compare drug utilization, with focus on CYP2D6, with that of a control group.

MATERIAL AND METHODS

The study population consisted of 46 patients with OLP, 60 sex- and age-matched control subjects for drug utilization evaluation and 223 healthy non-medicated controls for genotype comparison. DNA analysis was done using polymerase chain reaction and restriction fragment length polymorphism. The gene CYP2D6 was analyzed for the alleles CYP2D6*3,*4,*5,*6 and gene duplication. Drug utilization was evaluated according to Anatomical Therapeutic Chemical code, liver drug metabolism pathway and mono- or polytherapy.

RESULTS

Intake of drugs was significantly higher in the group of OLP patients in comparison with control subjects. The use of CYP2D6 substrates, inhibitors or inducers did not differ between OLP patients and controls. Predicted phenotype frequencies in OLP patients and healthy controls, respectively were as follows: ultrarapid metabolizers 2% and 5.8%, extensive metabolizers 52% and 49.8%, intermediate metabolizers 39% and 37.7% and poor metabolizers 7% and 6.7%.

CONCLUSIONS

We did not find a statistically significant difference in the frequency of CYP2D6 alleles between OLP patients and healthy controls. OLP patients used more medication than age- and sex-matched controls.

Oral lichen planus: A retrospective study of 110 Brazilian patients

Background

Oral lichen planus (OLP) is a chronic autoimmune disease characterized by multiple clinical presentations and a relatively high prevalence in the population. This retrospective patient record study investigated the profile of OLP in a group of Brazilian patients seen between 1989 and 2009.

Findings

The clinical records were analyzed and data such as gender, age, race, clinical presentation of OLP, site affected, presence of symptoms and extraoral manifestations of the disease, smoking habit, and consumption of alcoholic beverages were obtained. Among the 1822 records of patients with oral mucosal lesions, OLP was identified in 6.03%. Of these, 76.36% were females, with a mean age of 54 years, and 85% were whites. The reticular form was the most frequent (81.81%). Extraoral lesions were observed in 32.72% of the patients and painful symptoms were reported by 50.90%. The cheek mucosa was the site most affected (92.72%) and multiple oral lesions were observed in 77.27% of the patients. Among patients with OLP, 18.18% reported a smoking habit and 29.09% the consumption of alcoholic beverages.

Conclusions

This retrospective study showed a relatively high prevalence of OLP in the population studied, with a predominance of the disease among middle-aged white women and bilateral involvement of the cheek mucosa. Reticular lesions were the most frequent, followed by the erosive form which is mainly associated with painful symptoms. No relationship with tobacco or alcohol consumption was observed.

Mannose-binding lectin gene (MBL-2) polymorphism in oral lichen planus

TNF-α may be associated with the etiopathogenesis of oral lichen planus (OLP), and it has been suggested that polymorphism of mannose-binding lectin (MBL) increases the in vitro production of TNF- α. The aim of the present study was to assess the relevance of genetic diversity of MBL in OLP. The study sample comprised 90 individuals, 45 OLP patients and 45 healthy volunteers. MBL-2 gene was amplified using real-time PCR. Frequency of A/A genotype was 55.6% in OLP and 53.3% in healthy volunteers. Likewise, A/0 heterozygote genotype was found in 42.2% and 35.6%; 2.2% and 11.1%, had the recessive 0/0 genotype respectively. Frequencies of the "A" and "0" alleles were 77% and 23% in the OLP group and 71.2% in control group. There were no statistically significant differences regarding genotype frequency (p = 0.546) or allele frequency (p = 0.497). In conclusion, no significant association was found between polymorphism of MBL-2 gene and OLP.

Pathophysiology, etiologic factors, and clinical management of oral lichen planus, part I: facts and controversies

Lichen planus (LP) is an inflammatory disease of the stratified squamous epithelia of unknown etiology. LP affects most frequently the oral mucosa, but it may also involve other mucosa and the skin. Oral LP (OLP) most frequently affects woman aged between 30 and 60 years. Histopathologic examination typically shows orthokeratotic hyperkeratosis, basal cell degeneration, and a dense well-defined infiltrate of lymphocytes in the superficial dermis. OLP lesions may result from the induction of keratinocytes apoptosis by cytotoxic CD8+ T cells stimulated by a yet unidentified self-antigen on a genetically predisposed patient. The association of OLP with hepatitis C virus (HCV) has been more consistently demonstrated in the Mediterranean area. Although HCV RNA and HCV-specific CD4+ and CD8+ T cells have been retrieved in the mucosal lesions of patients with chronic HCV infection and OLP, the eventual pathophysiology of HCV in OLP lesions remains unclear. Available treatments of OLP are not curative, and many have potentially prominent side effects. The objectives of OLP management should be to prevent and screen for malignant transformation and alleviate symptoms on the long-term. Avoidance of potential precipitating drugs, tobacco, alcohol, and local trauma, as well as strict oral hygiene, is essential. The first-line pharmacologic treatment relies on topical steroids. Systemic steroids should be limited to the short-term cure of severe refractory OLP. Life-long clinical follow-up, at least annually, is fundamental.

Oral lichen planus: clinical features, etiology, treatment and management; a review of literature

Lichen planus is a chronic inflammatory mucocutaneous disease. Mucosal lesions are classified into six clinical forms and there is malignant potential for two forms of OLP; therefore, follow-up should be considered. There are many un-established etiological factors for OLP and some different treatment modalities are based on etiology. The aims of current OLP therapy are to eliminate mucosal erythema and ulceration, alleviate symptoms and reduce the risk of oral cancer. We have used review papers, case reports, cohort studies, and case-and-control studies published from 1985 to 2010 to prepare this review of literature.

Oral burning sensation: prevalence and gender differences in a Japanese population

BACKGROUND

Burning mouth syndrome (BMS) is characterized by an oral burning sensation (OBS) in the tongue or other oral mucous membrane in the absence of any clinical abnormal findings. It frequently affects middle-aged and aged women. Although there are many oral disorders with OBS besides BMS, the prevalence of OBS is unclear.

AIM

To investigate the prevalence of OBS and analyze the gender differences in a Japanese population.

METHODS

The study subjects were 2599 dental patients in two dental offices in Tokyo, Japan. The prevalence of OBS was investigated using a questionnaire.

RESULTS

The mean ages of the subjects were 42.7 +/- 13.8 (mean +/- SD) years of age in male and 40.1 +/- 15.4 (mean +/- SD) years of age in female. The prevalence of OBS "at present" was 2.8% of 1310 male subjects and 3.2% of 1289 female subjects. There was no statistically significant difference between them for each decade. The prevalence including "at present" and "in the past" were 9.3% in male subjects and 10.8% in female subjects; this difference was not statistically significant.

CONCLUSION

These findings fail to demonstrate a female predilection for OBS.

Epstein-Barr virus prevalence in oral squamous cell cancer and in potentially malignant oral disorders in an eastern Hungarian population

We tested 65, 44, and 116 patients with oral squamous cell cancer (OSCC), oral leukoplakia (OL), and oral lichen planus (OLP) against 68 age-matched controls for the presence of Epstein-Barr virus (EBV). Apparently healthy mucosa was simultaneously sampled and examined in all patients. Paraffin-embedded tissue sections of all EBV-positive patients with OSCC were examined for latent membrane protein-1 (LMP-1) expression (demonstrable in most EBV-associated malignancies) using immunohistochemistry. The prevalence of EBV in the controls and in OSCC, OL, and OLP lesions was 19.1%, 73.8%, 29.5%, and 46.6%, respectively, and 66.2%, 22.7%, and 31.9% in the healthy mucosa of patients, respectively. The prevalence of EBV in OSCC patients was significantly higher than in controls or in respective samples of the other two patient groups both in the lesion and in the healthy mucosa. Comparisons including only patients with EBV-negative lesions yielded similar results. Lesions of patients with OLP, but not of patients with OL, differed significantly from controls in EBV prevalence. In OSCC, LMP-1 expression was not detected, and EBV carriage was not significantly associated with any risk factors and did not influence the outcome. Although a high prevalence of EBV was found in OSCC, comparable carriage rates on healthy mucosa of patients indicated that an aetiological role of EBV is unlikely.

Progressive increase of human papillomavirus carriage rates in potentially malignant and malignant oral disorders with increasing malignant potential

INTRODUCTION

We investigated the potential role of human papillomaviruses (HPVs) in potentially malignant oral disorders, oral leukoplakia (OL) and oral lichen planus (OLP), and in oral squamous cell cancer (OSCC) in an Eastern Hungarian population with a high incidence of OSCC.

METHODS

Excised tumor samples (65 OSCC patients) and exfoliated cells from potentially malignant lesions (from 44 and 119 patients with OL and OLP, respectively) as well as from healthy controls (72 individuals) were analysed. OLPs were classified based on clinical appearance, 61 patients had erosive-atrophic lesions (associated with higher malignancy risk, EA-OLP) and 58 had non-erosive non-atrophic lesions (with lower risk of becoming malignant, non-EA-OLP), respectively. Exfoliated cells collected from apparently healthy mucosa accompanied each lesion sample. HPV was detected by MY/GP polymerase chain reaction (PCR) and genotyped by restriction analysis of amplimers. Copy numbers in lesions were determined using real-time PCR. Prevalence rates, copy number distributions, and association with risk factors and diseases were analysed using chi-square test, t-test, and logistic regression, respectively.

RESULTS

We detected HPVs significantly more frequently in lesions than in controls (P < or = 0.001 in all comparisons). HPV prevalence increased gradually with increasing severity of lesions (32.8, 40.9, and 47.7% in OLP, OL, and OSCC, respectively). Copy number distribution patterns roughly corresponded to prevalence rates, but OLP and OL were comparable. HPV prevalence differed significantly between EA-OLP and non-EA-OLP groups (42.6 vs. 22.4%); EA-OLP group showed a prevalence similar to that found in OL.

CONCLUSION

HPVs may be involved in the development or progression of not only OSCC but also of potentially malignant oral lesions.