Oral lichen planus. A review

Expression of Cluster of Differentiation 1a-Positive Langerhans Cells in Oral Lichen Planus

Background/Purpose:

Lichen planus is a T-cell-mediated mucocutaneous disorder characterized histopathologically by a band of chronic inflammatory cells in the subepithelial zone and degeneration of basal layer. The present study was aimed to evaluate the distribution and quantitative assessment of cluster of differentiation 1a (CD1a)-positive Langerhans cells (LCs) in oral lichen planus (OLP), thus to determine the role of LCs pertaining to the changes occurring in OLP.

Materials and Methods:

Five cases of normal oral mucosa and 20 cases of OLP were immunostained with CD1a antibody; the positive cells were counted manually in the photomicrographs and statistically analyzed using t-test, Mann–Whitney test, and Wilcoxon signed-rank test.

Results:

The average percentage of CD1a-positive LCs in normal subjects was 0.9%, and in the OLP cases higher percentage was observed (3.93%). The statistical comparison of these two parameters was significant (P=0.018). The degree of basal cell degeneration and density of subepithelial infiltrate on statistical comparison with the concentration of CD1a-positive LCs showed significant results.

Conclusion:

LCs play a pivotal role in the recruitment of CD4+ and CD8+ cells to the subepithelial region and basal keratinocytes apoptosis. A small number of study subjects, assessment of only CD1a molecule and LCs in the epidermis only were a few of the drawbacks of the study.

Black pepper and its bioactive constituent piperine: promising therapeutic strategies for oral lichen planus

Oral lichen planus (OLP) is a common T cell-mediated chronic inflammatory disease with malignant potential and unclear etiology. The present study suggests that antigen-specific mechanisms in which dentritic cells, T lymphocytes and NF-κB signaling pathway play critical roles, are involved in the pathogenesis of OLP. Additionally, it has been indicated that altered expression of cyclooxygenase 2 (COX-2) and imbalanced oxidant-antioxidant status as well as psychological issue may act as promoters to the development of OLP. Therapies for OLP are primarily aimed to control symptoms and a specific cure is not yet available. Black pepper and its principle bioactive compound piperine have been reported to possess remarkable pharmacological activities. Not only has piperine been evidenced to exhibit repressive effects on the maturation of dentritic cells, the proliferation, activation and function of T lymphocytes as well as the NF-κB signaling pathway, but also to suppress the overproduction of COX-2 and weaken the oxidative stress. Furthermore, piperine might be a possible agent for alleviating psychological disorders and preventing carcinogenesis. Given all these into consideration, piperine may be a novel and effective therapeutic strategy for OLP.

Memory T Cells (CD45RO) Role and Evaluation in Pathogenesis of Lichen Planus and Lichenoid Mucositis

INTRODUCTION

Memory T cells have the ability to survive in a quiescent state for longer periods and are responsible for the rapid responses on subsequent exposure to antigen. Analyzing memory T cells in Oral Lichen planus (OLP) and Lichenoid Mucositis (LM) suggest that these cells may play a role in the immunopathogenic mechanisms.

AIM

To identify and evaluate Memory T cells in Lichen Planus (LP), Lichenoid Mucositis (LM) and Normal Mucosa (NM) using CD45RO monoclonal antibody immunohistochemically.

MATERIALS AND METHODS

A total of 30 cases (15 cases of OLP and 15 cases of LM) clinically and histopathologically diagnosed, and 10 cases of NM were stained for CD45RO monoclonal antibody, immunohistochemically using Biotin Streptavidin method. Staining intensity of CD45RO expression was statistically analysed using Chi-square Test.

RESULTS

The present study demonstrated a higher expression of CD45RO in connective tissue layer of OLP (53.3% intense staining) when compared to LM (20% intense staining) and no intense staining in NM. The difference in staining intensity pattern between the study groups was statistically significant (p=0.014).

CONCLUSION

This study demonstrates a statistically significant rise in memory T cells in LP than in LM, indicating the possible different immunopathogenic mechanisms.

Immunohistochemical assessment of proliferating cell nuclear antigen protein expression in plaque, reticular and erosive types of oral lichen planus

BACKGROUND

Proliferating cell nuclear antigen (PCNA) is a nuclear protein synthesized in the late G1 and S-phase of the cell cycle. Immunodetection of this protein represents a useful marker of the proliferation status of lesions.

AIMS

The aim of this study is to evaluate the immunohistochemical expression of PCNA in oral lichen planus (OLP) and to assess the PCNA expression in a different layer of epithelium in different types of OLP.

SUBJECTS AND METHODS

A total of 96 cases of histologically proven OLP, 32 cases each of erosive, reticular and plaque type were selected. Two sections were taken from each one for H and E. Other sections were stained according to super sensitive polymer horseradish peroxidase method for identifying PCNA expression.

RESULTS

Of the three types of OLP, erosive type showed higher expression of PCNA (average 66.8%, minimum of 55% and maximum of 80.3%) followed by reticular (average 37.7%, minimum of 26% and maximum of 47%) and plaque type (average 17%, minimum of 5% and maximum of 25%) indicating increased proliferative activity. The erosive type also showed higher expression of PCNA in all the layers of epithelium followed by reticular and plaque type.

CONCLUSION

PCNA is a good marker to indicate proliferation status of disease. Out of three types, erosive type possess more proliferative ratio, chances of malignant changes is more in this type.

Phototherapy approaches in treatment of oral lichen planus

Oral lichen planus (OLP) is a chronic immunologic mucocutaneous inflammatory disease of the oral mucosa. Since the etiopathology of OLP is idiopathic, treatment is usually symptomatic, therefore showing low predictability. Currently, topical corticosteroids are widely accepted as the standard therapy. However, for patients unresponsive to standard therapy for OLP, new treatment modalities have been sought. Phototherapy has recently been accepted as an alternative or adjunctive treatment modality for many conditions in medicine and dentistry. The aim of this study is to present the advantages and disadvantages of the different kinds of phototherapy used in treatment of OLP (UV phototherapy, lasers, and photodynamic therapy). The main outcome measures compared were improvement of signs and symptoms and OLP recurrence. Although some phototherapy techniques in the selected articles have demonstrated limited effects, there is no solid basis in evidence for the effectiveness of any of these treatments for OLP. Therefore, further research, especially randomized controlled clinical trials with long-term follow-up, is needed to give any solid recommendation on the use of phototherapy in the field of OLP treatment.

Prevalence of oral mucosal lesions in an adult Iranian population

Background

Nowadays the importance of oral health to life quality is not obvious to anyone in our world. Oral lesions can interfere with daily social activities in involved patients through impacts on mastication, swallowing and speech and symptoms like xerostomia, halitosis or dysesthesia.

Objectives

To assess the prevalence and types of oral lesions in a general population in Rasht, Northern Province of Iran.

Patients and Methods

1581 people aged > 30 years old who were inhabitant of Rasht, Iran, enrolled in a cross-sectional study. For each individual a detailed questionnaire based on the world health organization (WHO) guidelines in order to diagnosis of the lesions was filled and it contained all the required data. Participants were divided into two groups with and without oral mucosal lesions and oral mucosal lesions were divided into two groups with and without. Demographic characteristics and clinical information including age, sex, smoking (cigarette and tobacco), opium consumption, medication and oral and dental hygiene were collected and compared between these two groups.

Results

The prevalence of mucosal lesions in our study was 19.4%. Our data demonstrated higher prevalence of oral mucosal lesions in males and young adults (30-40 years). The most common mucosal lesion among our participants was Fissured tongue(4%), followed by Fordyce granules(2.8%), geographic tongue(2.6%) , Pigmentation(2.5%), Candida(1.8%), Smoker Plate(1.6%), lingual Varices(1.5%), Petechiae(1.4%) and lingual labial(1.4%) . Leukoplakia was observed only in two people (0.1%).No case of malignant lesions was detected. No statistically significant difference was confirmed between the two groups regarding smoking, opium consumption, medication and oral and dental hygiene.

Conclusions

Our data has provided baseline information about epidemiologic aspects of oral mucosal lesions which can be valuable in organized national program targeting on oral health and hygiene in the society.

Serotonin transporter gene polymorphism (5-HTTLPR) in patients with oral lichen planus

BACKGROUND

Considerable evidence indicates that serotonergic mechanisms, particularly the serotonin transporter (5-HTT) may be involved in psychiatric alterations. Recent findings have demonstrated that depression and stress are influenced by polymorphism of the promoter region of 5-HTT (5-HTTLPR) and that the short allele (S) is associated with reduced transcriptional efficiency resulting in reduced serotonin expression and uptake. As psychiatric and genetic factors have been implicated in the pathogenesis of oral lichen planus (OLP), the purpose of the present study was to investigate 5-HTTLPR polymorphism in patients with OLP compared to control subjects.

SUBJECTS AND METHODS

Fifty-four subjects affected by OLP and 54 healthy volunteers were genotyped at 5-HTTLPR. The chi-squared test was used for statistical analysis. To investigate the association between the single nucleotide polymorphisms and risk of OLP, binary logistic regression models were fitted.

RESULTS

No statistical difference was observed between the genotype and allele frequency in the group of OLP and controls (p=0.51). Moreover no association between 5HTTLPR alleles and OLP was found in the multivariate analyses.

CONCLUSION

Our study demonstrates that polymorphism on the 5-HTTLPR is not associated with OLP pathogenesis.

Pimecrolimus (ELIDEL®) zur Behandlung des Lichen planus mucosae

Oral lichen planus (OLP) is a common chronic inflammatory disorder with criteria of auto-reactive disease. Treatment consists on topical application of corticosteroids, vitamin A derivates or cyclosporin. Calcineurin inhibitors as tacrolimus and pimecrolimus decrease the production of cytokines and inhibit T-cell proliferation. These substances have recently been introduced for local therapy of chronic inflammatory skin disorders. The aim of our study was to evaluate the effectiveness and side effects of local pimecrolimus in OLP. A group of five patients with histological proven OLP were treated with topical pimecrolimus 1% ointment twice daily to the affected area. Prior to treatment and after 7, 14, 28 and 42 days the lesions were assessed clinically and by photographs. The discomfort scores were evaluated by visual analogue scale (VAS) weekly. All five patients (median age 65.6 years) were female and showed involvement of the buccal mucosa. All lesions showed a reduction of inflammation activity during the treating period. The VAS scores decreased significantly under treatment (p=0,0014). Pimecrolimus ointment was tolerated well with no signs of itching or burning. However, 4 out of 5 patients complained about the reduced adherence properties of the cream. Although no complete remission of OLP has been observed in our series, signs of inflammatory activity of OLP as redness and burning sensations were reduced by topical pimecrolimus. Further controlled randomized studies have to be conducted to compare topical pimecrolimus with topical corticosteroid as standard therapy. The adherence properties of pimecrolimus 1% cream should be improved for intra-oral application.

An association between oral lichen planus and a persistently dry mouth

OBJECTIVES

The aim of this study was to investigate the relationship between oral lichen planus and dry mouth by comparing xerostomia scores of individuals with oral lichen planus to those of healthy matched controls.

STUDY DESIGN

Patients who had attended 1 of 2 centers for the management of oral lichen planus (n=116), along with age- and sex-matched control subjects (n=348), were sent a questionnaire. Nonresponders were invited to complete the questionnaire by telephone in lieu of mailing a reply. A standardized medical history was obtained for all subjects.

RESULTS

The difference between patients with oral lichen planus and control subjects for all xerostomia questions was statistically significant. In the lichen planus group, the mean xerostomia score was 20.4, whereas for control patients, the mean score was 14.7 (P <.001). Stepwise conditional logistic regression analysis for the matched case-control groups was performed.

CONCLUSION

The results demonstrate an association between oral lichen planus and xerostomia in some individuals.

Relationship of Oral Lichen Planus to Hepatitis C Virus in Southern Taiwan

Oral lichen planus (OLP) is a relatively common skin and oral disease that manifests as a mucous reaction to a variety of etiologic factors, including autoimmune disease, drug reaction, diabetes mellitus (DM), hypertension, hepatitis C virus (HCV), urolithiasis, psychogenic factors, and bacterial infection. The purpose of this study was to investigate the relationship between HCV infection and OLP as there is a high prevalence of HCV infection in Taiwan. A total of 1,075 subjects aged at least 15 years participated in the study. The total prevalence of OLP was 3% (32/1,075). OLP was significantly associated with DM (odds ratio, OR, 3.09) and HCV (OR, 2.05). Atrophic-erosive OLP (13/32) and reticular OLP (21/32) were significantly associated with HCV and DM, respectively. Logistic regression analysis showed that elevation of alanine aminotransferase (ALT) significantly increased the risk of atrophic-erosive OLP. We concluded that OLP is significantly associated with HCV and DM in southern Taiwan, particularly in HCV patients with elevated serum ALT levels and atrophic-erosive OLP.

Treatment of oral lichen planus with the 308-nm UVB excimer laser--early preliminary results in eight patients

BACKGROUND AND OBJECTIVES

Oral lichen planus (OLP) is a chronic disease of uncertain origin. Many patients with OLP are refractory to all available therapies. The 308-nm excimer laser was used as a possible additional method in the treatment of OLP.

STUDY DESIGN/MATERIALS AND METHODS

Eight patients with OLP were treated using the 308-nm UVB excimer laser.

RESULTS

Clinical improvement was achieved in six patients. Two patients showed complete remission, of which one patient showed recurrence of the lesions after 4 weeks.

CONCLUSION

The preliminary results in our opinion warrant further studies of this treatment.

Expression of hMSH2 protein of the human DNA mismatch repair system in oral lichen planus

Lichen planus is a mucocutaneous disease of inflammatory nature and unknown etiology. It is characterized by a cell-mediated immunological response to induced antigenic change in skin and/or mucosa. The possible malignant transformation of lichen planus remains a subject of controversial discussions in the literature. hMSH2 is one of the human DNA mismatch repair (hMMR) genes and it plays an important role in reducing mutation and maintaining genomic stability. hMSH2 alterations have been reported in oral squamous cell carcinoma and there are evidences suggesting the association between oral lichen planus and squamous cell carcinoma. In this study, we aim to investigate the immunolocalization of hMSH2 protein in oral lichen planus compared to oral normal mucosa epithelium. We examined the expression of hMSH2 protein by immunohistochemistry in twenty-six cases of oral lichen planus. Clinically, 12 of them were categorized into reticular subtype and 14 were atrophic/erosive. Ten cases of normal mucosa were added to the control group. Results showed that the percentage of positive cells to hMSH2 was smaller in reticular (46.54%; p=0,006) and atrophic/erosive (48.79%; p=0,028) subtypes of oral lichen planus compared to normal mucosa (61.29%). The reduced expression of hMSH2 protein in oral lichen planus suggests that this lesion is more susceptible to mutation and therefore facilitate the development of oral squamous cell carcinoma.

Oral lichen planus part I: epidemiology, clinics, etiology, immunopathogeny, and diagnosis

This article presents a review of the literature on oral lichen planus, focusing on important aspects of its epidemiology, etiopathogeny, and clinical manifestations. The oral form is an important clinical presentation of lichen planus. It may precede or accompany the skin lesions, or it may be the only manifestation of the disease. Dermatologists, dentists, otorhinolaryngologists, and other specialists who deal with the oral cavity must be aware of this disease so they can diagnose, treat, and keep these patients under observation.

[Oral precancerous conditions--an overview]

Precancerous conditions are defined as a generalized state associated with a significantly increased risk of cancer. For the oral and perioral region, sideropenic dysphagia, oral lichen planus (OLP), oral submucous fibrosis (OSF), syphilis, discoid lupus erythematosus, xeroderma pigmentosum as well as epidermolysis bullosa play a role as precancerous conditions. The number of published cases of oral or perioral malignant transformation for some of these diseases is small. In addition, carcinomas of the tongue and the oral cavity associated with syphilis are of historical interest, although publications in the 1990s still reported positive serology of syphilis and carcinomas of the tongue. OLP is still controversially discussed as to its premalignant nature. Transformation rates have been reported between 0% and 5.6%. Recent prospective studies have revealed that possibly oral lichenoid reactions (OLR) are more likely to form the basis of malignant transformation as compared to the classic OLP. The differentiation between OLP and OLR is difficult both from clinical and histopathological aspects. The second most important precancerous condition is oral submucous fibrosis, which is caused by betel quid chewing. OSF is most prevalent in South and Southeast Asia. The transformation rate is as high as 7.6% making OSF one of the most important precancerous conditions of the oral region.

Thermal sensation and pain in oral lichen planus and lichenoid reaction

BACKGROUND

Our previous findings in oral lichen planus (OLP) and lichenoid reactions (LR) raised the question whether the histopathological changes observed in sensory and autonomic innervation produce oral sensory disorders.

METHODS

Spontaneous pain was assessed using the Visual Analogue Scale (VAS). Thermal pain thresholds were measured with a contact thermostimulator and mechanical pain thresholds with an electronic algometer.

RESULTS

Patients with OLP reported a higher intensity of spontaneous pain than LR patients (P = 0.001). Even erosive LRs were relatively painless. No thermal or mechanical hyperalgesia was detected in oral lesions. Highest separate cold pain threshold was measured in lesions affected by intense Candida growth.

CONCLUSION

Together with previous histological findings, the present data suggest that increased somatic innervation and sympathetic denervation do not promote clinical pain sensitivity or hyperalgesia in oral mucosa and that these sensory functions are not affected by OLP and LR. Candida growth may function as secondary irritant modulating the pain responses.

Cost-effectiveness of screening for the possible development of cancer in patients with oral lichen planus

INTRODUCTION

Several authors have expressed the view that patients with oral lichen planus (OLP) are at increased risk of developing oral cancer. Since OLP cannot be effectively treated, regular screening for the possible development of oral cancer might be considered.

OBJECTIVES

(i) To calculate costs and effectiveness of screening for oral cancer in OLP patients with a decision model; (ii) to compare the cost-effectiveness of different screening scenarios; and (iii) to perform a sensitivity analysis of several variables used in this model.

METHODS

Costs and effectiveness of a population of 100,000 OLP patients, being either screened or not screened for oral cancer, were calculated for the period of 1 year. Health gain was expressed as quality adjusted live years (QALY's) and equivalent lives saved (ELS). Cost-effectiveness was expressed as extra costs (costs of screening minus costs of no screening) per ELS. Then, the outcome was compared with the cost-effectiveness of a different screening scenario. Finally, the effect of varying the variables: (i) costs of cancer treatment; (ii) annual malignant transformation rate (MTR); (iii) sensitivity and specificity of an oral examination; and (iv) proportion of cancers found in stage I on extra costs per ELS were assessed in a sensitivity analysis.

RESULTS

The health gain from screening was 592 QALY's or the equivalent of 23.68 lives saved, costing 1,265,229 dollars, meaning that one ELS costed 53,430 dollars. Increase of cancer-treatment costs will significantly decrease the costs per ELS. When the MTR is lower than 0.4% per year, extra costs per ELS will increase exponentially. The effect of sensitivity and specificity of an oral examination in detecting oral cancer on cost-effectiveness seems to be substantial. When the proportion of cancers found in stage I can be increased from 40% (without screening) up to at least 60% after screening, extra costs per ELS will decrease exponentially.

CONCLUSIONS

Screening for oral cancer in OLP patients, based on the presently used model, seems attractive. However, varying the several variables in the decision model has a significant impact on the final costs and effectiveness. Only, when additional information about these variables will become available, a more precise and realistic calculation can be performed.

Identification of the AgNORs, PCNA and ck16 proteins in oral lichen planus lesions

The expression of proliferating cell nuclear antigen (PCNA), cytokeratin 16 (ck16) and Ag nucleolar organizer regions (AgNORs) were assessed in 20 cases of lichen planus, 20 cases of keratosis and 20 cases of normal oral mucosa in order to evaluate the rate of keratinocyte proliferation in these tissues. Three hundred cells were counted in each sample: 100 basal cells, 100 suprabasal cells and 100 squamous cells. The mean number of AgNORs and the percentage of PCNA positive cells were calculated. Except from similar staining of suprabasal cells of lichen planus and keratosis, PCNA and AgNORs values were higher in all layers of lichen planus than in both keratosis and normal oral mucosa. The three groups showed similar ck16 immunostaining: all of the cells were positive, except those of the basal layer. The results suggest that the keratinocyte proliferation index is higher in lichen planus than in keratosis and normal mucosa. Besides, ck16 should not be used to differentiate the entities studied.

Management of oral lichen planus

Lichen planus is a relatively common disorder of the stratified squamous epithelia. Most dental and medical practitioners see patients with lichen planus, but not all are recognized as having the disease. Patients with lichen planus may have concomitant involvement of the disease in multiple sites. Oral lichen planus lesions usually have a distinctive clinical morphology and characteristic distribution, but oral lichen planus may also present a confusing array of patterns and forms, and other disorders may clinically mimic oral lichen planus. The etiopathogenesis of lichen planus appears to be complex, with interactions between genetic, environmental, and lifestyle factors. Much has now been clarified about the etiopathogenic mechanisms involved and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory in all cases and there is as yet no definitive treatment that results in long term remission, but there have been advances in the control of the condition. Amongst the many treatments available, high potency topical corticosteroids remain the most reliably effective, though topical cyclosporine, topical tacrolimus, or systemic corticosteroids may be indicated in patients whose condition is unresponsive to topical corticosteroids.

Oral lichen planus: a review

Oral lichen planus is a disease that can persist in some patients for a long time. The buccal mucosa, tongue and gingiva are the most common sites, whereas palatal lesions are uncommon. Oral lichen planus affects women more often than men in a ratio of 2:3. It can present in a number of forms: reticular, papular, plaque-like, erosive, atrophic and bullous. The question of malignant transformation of oral lichen planus remains controversial. The management can be non-surgical or surgical and the choice of treatment may vary from patient to patient and depends on the choice of the clinician.

Malignant transformation of oral lichen planus

AIMS

To investigate the malignant potential of oral lichen planus (OLP), a common mucocutaneous disease of unknown aetiology. The malignant potential of OLP is still controversial, with studies reporting malignant transformation rates of between 0 and 5.6%. We also aimed to identify factors that might be associated with malignant transformation.

METHODS

We retrospectively reviewed the records of 832 patients with histologically confirmed OLP treated at the Dental Hospital, Newcastle upon Tyne during the period 1983-1996.

RESULTS

Of these 832 patients, a total of seven (0.8%) developed intra-oral squamous cell carcinoma (SCC), including three cases of carcinoma in situ. It was noted that OLP patients with SCC are more likely to be women, relatively young and have a low tobacco and alcohol intake. However, they had a good long-term prognosis.

CONCLUSIONS

We conclude that the risk of malignant transformation in OLP is real but not high. Clinicians should have a higher index of suspicion of the possibility of malignancy developing in OLP, because such patients are different from typical patients who develop oral malignancy. Follow-up for at least 6 years is recommended.

Immunocompetent cells in amalgam-associated oral lichenoid contact lesions

Inflammatory cells in amalgam-associated, oral lichenoid contact lesions (OLL) were studied in 19 patients by immunocytochemistry using monoclonal antibodies. Ten of the patients displayed allergic patch test (PT) reactions to several mercury compounds and nine were negative. The immunocytochemical quantification showed a uniform composition of the inflammatory mononuclear cells in the two study groups. The number of HLA-D/DR-positive dendritic cells (P<0.001) and CD1a-positive Langerhans cells (P=0.035) was significantly lower in the PT-negative than PT-positive patients. HLA-D/DR expression on keratinocytes varied from negative to full thickness staining of the epithelium. HLA-D/DR expression in the full thickness of epithelium (3) or through the basal and spinous cell layers (2) was seen in 5 of 8 PT-positive patients, whereas none of the PT-negative patients had this staining pattern (P=0.045). These patients also showed a good clinical response after amalgam removal. Consequently, OLL may represent a true delayed hypersensitivity reaction with a trans-epithelial route of entrance of the metal haptens released from dental restorative materials.

Efficacy of topical mesalazine compared with clobetasol propionate in treatment of symptomatic oral lichen planus

OBJECTIVE

To compare topically applied mesalazine (5-aminosalicylic acid) to topically applied clobetasol propionate in the treatment of patients suffering from symptomatic oral lichen planus.

DESIGN

Randomized controlled longitudinal investigation.

PATIENTS AND METHODS

Twenty-five out-patients suffering from oral lichen planus and referred to the Department of Oral Pathology and Oral Medicine of the University of Milan, Italy, during the period January to August 1997. Patients were randomly allocated (Group A and Group B) to treatment with mesalazine 5% or clobetasol propionate 0.05%. The drugs were topically applied twice daily for 4 weeks. Discomfort and pain were evaluated by the patient before and after treatment using a Visual Analogue Scale from zero (no pain) to 10 (extreme pain). Results were statistically evaluated by a Mann-Whitney U test.

RESULTS

The two pharmacological regimens obtained partial and complete absence of symptoms. In particular, the mesalazine tested group disclosed 57% complete absence of symptoms, 21.3% partial response and 9% no response. No statistically relevant difference has been detected between the two regimens.

CONCLUSIONS

The results of this preliminary study, if confirmed by further investigations, suggest that mesalazine might be considered an alternative to clobetasol propionate for treatment of symptomatic oral lichen planus.

Analysis of desquamative gingivitis using direct immunofluorescence in conjunction with histology

Chronic desquamative gingivitis (DG) is a common condition often first recognized by periodontists. DG is characterized clinically by erythema with epithelial desquamation, ulceration, and/or the presence of vesiculobullous lesions of the free and attached gingiva. However, DG is actually a clinical manifestation of several different disease processes, particularly lichen planus and benign mucous membrane pemphigoid. Correct diagnosis in DG is critical since proper treatment and follow-up will depend on which disease is involved. However, the diseases that cause DG frequently present diagnostic problems because their lesions often resemble each other clinically and routine histological examination sometimes cannot differentiate between them. Thus, immunohistology, particularly immunofluorescence, is increasingly being used with routine histology to more accurately diagnose DG diseases. This article reviews our experience over the past 10 years in the diagnosis of 72 cases of DG using direct immunofluorescent (DIF) in conjunction with histology and clinical evaluation. Of the 72 DG cases in this study, 30 cases were diagnosed as erosive lichen planus or lichenoid mucositis; 29 cases were diagnosed as benign mucous membrane pemphigoid; 2 cases each of linear IgA disease and pemphigus vulgaris were diagnosed; there was 1 case of bullous pemphigoid; and 1 suspected case of paraneoplastic pemphigus. Even with DIF analysis, 7 cases could not be definitively assigned a particular cause. DIF analysis is not only proving very useful for differential diagnosis, but also adds insight into possible pathogenic mechanisms of DG.

Update on oral lichen planus: etiopathogenesis and management

Lichen planus (LP) is a relatively common disorder of the stratified squamous epithelia, which is, in many ways, an enigma. This paper is the consensus outcome of a workshop held in Switzerland in 1995, involving a selection of clinicians and scientists with an interest in the condition and its management. The oral (OLP) eruptions usually have a distinct clinical morphology and characteristic distribution, but OLP may also present a confusing array of patterns and forms, and other disorders may clinically simulate OLP. Lesions may affect other mucosae and/or skin. Lichen planus is probably of multifactorial origin, sometimes induced by drugs or dental materials, often idiopathic, and with an immunopathogenesis involving T-cells in particular. The etiopathogenesis appears to be complex, with interactions between and among genetic, environmental, and lifestyle factors, but much has now been clarified about the mechanisms involved, and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory, and there is as yet no definitive treatment, but there have been advances in the control of the condition. There is no curative treatment available; immunomodulation, however, can control the condition. Based on the observed increased risk of malignant development, OLP patients should be offered regular follow-up examination from two to four times annually and asked to report any changes in their lesions and/or symptoms. Follow-up may be particularly important in patients with atrophic/ulcerative/erosive affections of the tongue, the gingiva, or the buccal mucosa. Much more research is required into the genetic and environmental aspects of lichen planus, into the premalignant potential, and into the possible associations with chronic liver, and other disorders. More clinical studies are required into the possible efficacy of immunomodulatory drugs such as pentoxifylline and thalidomide.

In vitro lymphocyte proliferation test in the diagnosis of oral mucosal hypersensitivity reactions to dental amalgam

Patch testing was carried out in 23 patients with oral lichenoid lesions (OLL) topographically related to dental amalgam fillings. Twelve patients displayed positive reactions to several mercury compounds, whereas 11 patients were negative. An in vitro lymphocyte proliferation (LyPro) test was carried out using different mercury compounds and other metal salts. Mercuric chloride and phenyl mercuric acetate caused positive proliferation in 3/12 patch test-positive and in 5/11 negative patients. One out of seven healthy control subjects had a positive LyPro result. The mean stimulation index (SI) values between the patient groups or compared with the control subjects did not differ significantly. Zinc, tin, copper or silver salts caused in vitro lymphocyte stimulation in most of the patients and in healthy control people. Total (14) or partial (4) replacement of amalgam fillings was carried out in 18 patients. Complete healing of lichenoid lesions was seen in 4/6 LyPro test-positive and in 5/10 patch test-positive patients at follow-up examinations 12 months after the replacement of amalgam fillings. The in vitro proliferation assay seems not to be a specific test for identifying the patients who would benefit from amalgam replacement.

Potentially malignant epithelial oral lesions: discrepancies between clinical and histological diagnosis

OBJECTIVE

To evaluate the discrepancy index between the clinical and histological diagnosis and the prevalence of epithelial dysplasia and carcinoma in 45 patients with potentially malignant epithelial oral lesions (PMEL).

PATIENTS AND METHODS

We submitted 45 patients with PMEL to clinical examination and obtained a biopsy from each. The results of histological diagnosis were compared to the clinical diagnosis.

RESULTS

Clinical diagnosis showed that the most common PMEL was leukoplakia followed by lichen planus and by actinic cheilitis associated with leukoplakia. The most common site was the buccal mucosa. Histological diagnosis revealed that 46.7% of the PMEL were lichen planus. The discrepancy index between clinical and histological diagnosis was 24.4%. The higher discrepancy index occurred among leukoplakias. The prevalence of epithelial dysplasia and carcinoma was 17.8%.

CONCLUSIONS

We conclude that all PMEL should be submitted to a microscopic analysis because the discrepancy between clinical and histological diagnosis was present in a quarter of these lesions. Otherwise, the epithelial dysplasia and carcinoma were more frequent in the leukoplakias.

Clinical characteristics and treatment of patients with oral lichen planus in Israel

Oral lichen planus (OLP) has a multiple-site involvement, with the buccal mucosa being the most prevalent. A possible relationship between OLP and the risk of malignancies in the involved site is documented. The characteristics of OLP have been studied in different populations; however, no similar studies have been conducted in any Jewish population. The purpose of this study was to evaluate the natural history of OLP in Israeli Jewish patients. Data were collected from 157 charts of patients with histologically confirmed OLP. No evidence suggesting a connection between OLP and diabetes, cardiovascular disease, smoking, alcohol use, or positive Candida culture was found. Skin involvement of lichen planus was found in one fifth of the patients. Symptomatic OLP was noted in half of the patients, mainly in those with the erosive form. In 65% of the patients with symptoms, improvement by more than 50% was shown within 2 weeks of steroid use. The transformation rate of 1.3% of OLP into malignancy was observed in the entire group. A constant follow-up for contributing symptoms and for early diagnosis of suspected transformed lesions is of utmost importance.

Oral mucosal changes and associated factors among male industrial workers with or without access to subsidized dental care

Oral mucosal changes and associated factors were studied among male industrial workers in southern Finland. Two groups, with or without access to an employer-provided dental benefit scheme, were compared. A multiple-choice questionnaire followed by clinical examinations was completed by 325 (81%) subsidized workers and 174 (69%) controls. In both groups 52% of the subjects had some oral mucosal change, and there were no significant differences between the groups in the location distribution of the changes. Smoking was significantly associated with redness of the oral mucosa (p < 0.001), coating (p < 0.001), and leukoplakia (p < 0.01), whereas denture wearing was associated with ulcers (p < 0.05), hyperplasia (p < 0.001), and redness (p < 0.001). Among denture wearers non-acceptable dentures were significantly associated with hyperplasia (p < 0.001). The subsidized group had better dentures, although this did not significantly benefit their oral mucosal status.

Assessing the characteristics of patients with oral lichen planus

The authors assessed the medical history, lifestyles and health habits of 146 patients with oral lichen planus as confirmed by biopsy. The results support a relationship between stress and the development of oral lichen planus. Fifty-one percent of the subjects reported that they had experienced stressful events at the time of the lichen planus onset. Practitioners may want to consider the benefits of stress management and bereavement counseling in managing patients with oral lichen planus.

Life-style survey of patients with oral lichenoid reactions

The occurrence of different life-style patterns, including marital status, educational level, nutrition, tobacco and alcohol use, and frequency of physical activity, in patients with oral lichenoid reactions (OLR) in total or partial contact with amalgam fillings was examined. When compared with an age- and sex-matched control group, the daily intake of carbohydrates, fibers, and iron was statistically significantly higher in the OLR patients. Regarding marital status, there was a statistically significant difference between the OLR patients and the control subjects, the former group containing more people who were divorced or whose spouse had died. The frequency of physical activity was also statistically significantly higher in the OLR patients than in the control group. Hypothetical mechanisms that may lie behind the results obtained are discussed.

IL-1 alpha and IL-6 production by oral and skin keratinocytes: similarities and differences in response to cytokine treatment in vitro

IL-1 alpha and IL-6 are important pro-inflammatory and immunomodulatory cytokines and their production by oral (OK) and skin keratinocytes (SK) was compared. OK and SK produced IL-1 alpha, but not IL-6, constitutively. TNF alpha stimulation increased IL-1 alpha production by both cell types and exhibited synergy with interferon gamma (IFN gamma), although the latter had no effect by itself. In contrast, both cell types produced IL-6 in response to TNF alpha, IFN gamma or IL-4, and IFN gamma and IL-4 exhibited synergy with TNF alpha. For all cytokines the levels of IL-6 production were greater for OK than SK and OK, but not SK, produced IL-6 in response to IL-1 alpha stimulation. In addition, the IL-6 response to IL-4 stimulation was more rapid for OK than SK. These observations may explain the similarities and differences in wound healing and immuno-inflammatory diseases affecting the skin and oral mucosa.

Psychologic aspects of patients with oral lichenoid reactions

Psychologic aspects of 49 patients with oral lichenoid reactions (OLR) in contact with amalgam fillings were studied and compared with an age- and sex-matched control group. Psychologic factors such as personality, psychologic functioning, and quality of life were determined by using the Karolinska Scales of Personality (KSP), an additional Personality Scale (PS), a Psychological Functioning Scale (PFS), and a Quality of Life Scale (QLS). With regard to personality the OLR patients had significantly higher scores on the muscular tension and suspicion scales and significantly lower scores on the indirect aggression scale. In addition, the OLR patients were significantly more worried about their health and more helpful. With regard to psychologic functioning the OLR patients had significantly more sad thoughts, became dizzy more easily, found it harder to imagine themselves free from anxiety, and had more difficulty in concentrating. The results indicated that OLR patients had a tendency to be depressive. The need for a systemic investigation including odontologic, medical, and psychologic aspects was expressed.

Destruction of the epithelial anchoring system in lichen planus

To find out whether the epithelial anchoring system shows any alterations in lichen planus, we examined the distribution of type VII collagen, alpha 6 beta 4 integrin, and kalinin in lesions of lichen planus. These molecules were chosen because they are structural components of anchoring fibrils, hemidesmosome-associated complexes, and anchoring filaments. The localization of type VII collagen in lichen planus was strikingly different from that in nonaffected mucosa or dermis or in other mucocutaneous lesions. In the normal mucosa, type VII collagen was localized only at the basement membrane zone. In lichen planus, type VII collagen was present not only in the basement membrane area but also in streaked patterns deep in the connective tissue. The hemidesmosome-associated complex, alpha 6 beta 4 integrin, was localized at the basal aspect of basal epithelial cells of nonaffected sites, but was diffuse and discontinuous in lichen planus lesions. Most of the basal keratinocytes, however, stained for this integrin. Kalinin staining was discontinuous in lichen planus lesions. Often, finger-like projections of kalinin staining were found protruding into the connective tissue stroma. Kalinin was localized at the basement membrane zone of the nonaffected tissue and other mucocutaneous lesions. These results indicate that in cutaneous and mucosal lichen planus, the epithelial anchoring system is disturbed.

Photochemotherapy of oral lichen planus. A controlled study

Photochemotherapy with 8-methoxypsoralen and long-wave ultraviolet light (PUVA) has become a useful alternative in dermatologic therapy. PUVA therapy has been successfully used in the treatment of severe psoriasis and cutaneous lichen planus. The aim of this investigation was to use PUVA in the treatment of oral lichen planus (OLP). Eighteen patients with long-standing, bilateral, and severe OLP of the buccal mucosa participated in the investigation. A dose of 0.6 mg/kg 8-methoxypsoralen was administered orally 2 hours before long-wave ultraviolet light irradiation was done. The patients were randomly assigned to treatment of the left or right side of the buccal mucosa. The irradiation therapy was given 12 times at intervals of 2 to 3 days, and the patients received a total average dosage of 16.5 J/cm2. The results showed that 13 treated sites compared with six control sites responded significantly favorable to PUVA therapy. Two patients dropped out because of side effects that were similar to those seen after whole-body irradiation PUVA treatment. The follow up times was 12 months. The conclusion of this study is that PUVA seems to be effective in the treatment of OLP and should be considered in severe cases of OLP.

Topical cyclosporin in oral lichen planus: a controlled, randomized, prospective trial

The published studies of topical cyclosporin (CyA) therapy in chronic oral lichen planus (OLP) have shown conflicting results. We report an investigator-blinded study of 13 patients with OLP, who were randomly assigned to treatment with CyA (500 mg as a swish-and-spit medication for 5 min three times daily) or a corticosteroid oral paste (triamcinolone acetonide). The duration of treatment was 6 weeks. Thereafter, patients on corticosteroid therapy were treated with CyA. Only slight, transient clinical improvement was observed in both groups after 6 weeks of treatment, compared with baseline. No significant differences could be demonstrated between the two groups. CyA therapy following corticosteroid treatment did not produce any further clinical improvement. During follow-up of the disease for up to 1 year after treatment, neither the CyA nor the corticosteroid group exhibited long-term improvement in disease activity. Contradictory results from earlier reports are discussed.

Altered expression of extracellular matrix proteins and integrins in oral lichen planus (OLP)

The immunohistochemical distribution of collagens type I, III, IV, V, VI, of undulin and tenascin, and of integrins alpha 2, alpha 3, alpha 4, alpha 5, alpha 6 and beta 4, was studied in 14 biopsies of oral lichen planus (OLP), 5 biopsies of orthokeratinized gingiva and 4 biopsies of oral fibrous hyperplasia. The localization of extracellular matrix proteins showed altered expression in OLP when compared to normal oral mucosa, with two principal patterns corresponding to the reticular or atrophic type. Whereas in the reticular type a focal loss of immunoreactivity for collagen types I, III, V, VI and undulin was noted in areas with a cellular infiltrate, in the atrophic variant almost complete loss of immunoreactivity of the subepithelial extracellular matrix was found. There was no clear correlation between the distribution of extracellular matrix proteins and their integrin receptors. The present findings suggest that the autoimmune reaction in OLP might not be primarily targeted to oral keratinocytes but to an unknown antigen in the connective tissue stroma. The changes in the subepithelial extracellular matrix associated with the inflammatory reaction might, especially in the atrophic variant, impair the cross-talk between epithelium and mesenchyme and favour both the loss of barrier function and the development of erosions in the clinical course of the disease.

Serologic and molecular analysis of the HLA system in Israeli Jewish patients with oral erosive lichen planus

Oral erosive lichen planus is a distinct subtype of the common dermatosis lichen planus. Although the etiology of lichen planus is still obscure, it is known that cell-mediated immune mechanisms and genetic factors underlie its pathogenesis. Previous studies have found an association between lichen planus and HLA-DR3 or DR9 in different population groups. The present work was designed to elucidate, at the serologic and molecular levels, whether and which HLA genes are associated with oral erosive lichen planus in Israeli Jewish patients. A significant association with HLA-DR2 (RR = 4.7; pc < 0.0013) and a decrease in DR4 (RR = 0.3; p < 0.03) among the patients were noted. Oligotyping of DR2 alleles showed the presence of all three common variants (DRB1*1501, DRB1*1502 and DRB1*1601) in the patients, although none of the variants was overrepresented significantly. Three possible explanations for the role of HLA genes in the predisposition to oral erosive lichen planus are discussed. The most attractive theory for the pathogenesis of the disease seems to include the involvement of non-classical HLA genes.

A clinical investigation of the management of oral lichen planus with CO 2 laser surgery

Ten patients with an established histologic diagnosis of lichen planus on various sites of the oral cavity were treated with CO 2 laser therapy under local anesthesia. Power output of 5 W at continuous mode was applied to vaporize the lesions. Eradication was achieved by aiming the laser in a moving criss-cross pattern with defocused spatial overlap. Depth of removal was subepithelial. No suturing of the wound was done. Follow-up occurred at intervals from 6 months to 4 years. The average length was about 3 years. Postlaser healing was uneventful, with little pain, swelling, or bleeding. There was immediate relief in all patients of associated burning sensations and a tolerance to hot and spicy foods. This symptomatic improvement lasted throughout the follow-up. Reepithelialization produced little visible scarring, and the mucosa color and texture were close to normal. Alterations in the immunologic status of the patients were implicated. Histologic rebiopsy in two cases suggested significant improvement, normalization of the epithelium, and a reduction of the subepithelial infiltrate. The CO 2 laser is effective in the immediate relief of symptoms and contributes to the clinical improvement of oral lichen planus. Immunologic studies and long-term follow-up are suggested.

The oral mucosa as a mirror of general health or disease

There is a close relationship between general health/disease and oral mucosal reactions. Many diseases show unspecific or specific changes which may evolve throughout the course of the disease but the mucosal reaction may also constitute the initial clinical sign of the disease. Among the broad spectrum of conditions/diseases, three have been selected for this review--HIV/AIDS, Sjögren's syndrome and lichen planus. They illustrate how general disease may be mirrored in the oral mucosa. An attempt has been made to describe the scientific frontiers and to select pertinent key or review articles or books from among the huge amount of literature published in recent years.