Oral epithelial dysplasia with lymphocytic immune response: clinicopathological characterisation of 44 cases.

AIMS: Oral epithelial dysplasia (OED) often exhibits a lymphocytic/lichenoid immune response (LIR), imparting histological resemblance to lichenoid mucositis and rendering diagnosis challenging. The clinical appearances of OED and lichenoid inflammatory processes are generally divergent, presenting as well-demarcated hyperkeratotic plaques and diffuse white and/or red mucosal change with variably prominent Wickham striae, respectively. To date, clinicopathological characterisation of OED with LIR, including clinical/gross appearance, has not been depicted. METHODS AND RESULTS: Cases of solitary OED with LIR for which a clinical photograph was available were identified in the authors' institutional files. Clinical and histological features were documented. In 44 identified cases, dysplasia was mild (19 of 44, 43.2%), moderate (19 of 44, 43.2%) and severe (six of 44, 13.6%). Clinically/grossly, all 44 cases (100.0%), presented as well-demarcated hyperkeratotic plaques lacking diffuse white-and-red mucosal change or Wickham striae. Histologically, OED with LIR exhibited numerous 'lichenoid' features beyond the lymphocytic band in the superficial lamina propria, including: leucocyte transmigration (38 of 44, 86.4%), spongiosis (37 of 44, 84.1%), Civatte/colloid bodies (36 of 44, 81.8%), basal cell degeneration (29 of 45, 65.9%), sawtooth rete ridges (11 of 44, 25.0%) and subepithelial clefting (7 of 44, 15.9%). CONCLUSIONS: Virtually any lichenoid histological feature may be seen in OED with LIR, representing a significant diagnostic pitfall. The typical clinical appearance of OED with LIR is of a well-demarcated hyperkeratotic plaque, characteristic of keratinising dysplasia and devoid of lichenoid features. This suggests that pathologist access to clinical photographs during diagnostic interpretation of biopsied white lesions, which represents opportunity to perform gross examination of the disease process, may reduce interobserver variability and improve diagnostic accuracy in this challenging differential diagnosis.

Autoimmunity and epithelial dysplasia in patients with oral lichenoid diseases.

OBJECTIVES: The primary objective of this study was to explore relationship between autoimmunity and epithelial dysplasia in patients with oral lichenoid diseases. MATERIALS AND METHODS: A total of 66 patients with oral lichen planus (OLP), 35 with oral lichenoid lesion (OLL), and 85 with oral lichenoid drug reaction (OLDR) were enrolled. OLP, OLL, and OLDR were diagnosed following the definitions of the modified World Health Organization criteria, except for the absence of epithelial dysplasia. All patients underwent diagnostic incisional biopsy and adjunctive direct immunofluorescence assays. An indirect immunofluorescence assay was conducted to determine the antinuclear antibody (ANA) positivity. RESULTS: OLP and OLDR patients with epithelial dysplasia demonstrated higher prevalence of serum ANA positivity compared to those without epithelial dysplasia. Elevated serum levels of high sensitivity-C reactive proteins were observed in the OLP, OLL, and OLDR patients with epithelial dysplasia. In the DIF analysis, patients with epithelial dysplasia in the OLP exhibited a higher prevalence of C3 deposition in the basement membrane zone. CONCLUSIONS: This study proposed that autoimmunity may contribute to elevating levels of focal and chronic systemic inflammation, potentially influencing abnormal wound healing and development of dysplastic changes in the oral epithelium among patients with oral lichenoid disease.

Camrelizumab-induced oral lichenoid reaction with subepithelial CD4+ T-cell infiltration.

INTRODUCTION: Camrelizumab is a novel anti-programed cell death-1 (PD-1) antibody that has been investigated for the treatment of various malignancies. Increasing immune-related adverse events have been reported in clinical practice, with CD4+ T-cell-mediated-reactive cutaneous capillary endothelial proliferation being the most common. Camrelizumab-induced oral lichenoid reaction (OLR) appears to be a rare adverse effect compared with other anti-PD therapies induced OLR, with the main pathogenesis of activated CD8+ T cells mediating autoimmune reactions. Herein, we report a rare case of camrelizumab-induced OLR and a possible pathogenic mechanism of subepithelial CD4+ T-cell infiltration. CASE REPORT: A 57-year-old male patient, who was diagnosed with metastatic esophageal squamous cell carcinoma three years prior, presented with a two-month history of oral erosion that developed while under camrelizumab therapy. Diffuse erythematous and erosive lesions surrounded by bilateral white lesions on the buccal mucosa were detected in his physical examination. Hematoxylin and eosin staining of the lesions revealed the presence of basal keratinocyte degeneration and band-like subepithelial T-cell infiltration. The immunostaining for CD4 on T-cell was positive, while CD8 were sporadically positive. Flow cytometry showed a gradual increase in the CD4+ T-cell proportion in the peripheral blood, with the CD8+ T-cell percentage almost unchanged and in the normal range. We obtained a score of 6 based on the Naranjo algorithm, which means a probable adverse drug reaction. MANAGEMENT AND OUTCOME: The patient exhibited notable improvement after two weeks of treatment with topical glucocorticoid without regulating his immunotherapy, and remained in stable condition in the follow-up. DISCUSSION: This case may offer new insight to clinicians on the pathogenesis of anti-PD-1-induced OLR. More critically, it may provide some ideas for a more precise anti-PD therapy or corresponding combination therapy for patients becoming resistant to immunotherapy due to exhausted CD4+ T-cell responses in the tumor microenvironment.

Oral lichenoid drug eruption due to osimertinib for lung cancer.

INTRODUCTION: Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR) are linked with side effects involving skin and mucosa. Herein, we present a unique case of oral lichenoid drug eruption (LDE) in a patient treated with osimertinib. CASE REPORT: A 75-year-old woman was diagnosed with metastatic EGFR-mutated lung adenocarcinoma, and started on osimertinib 80 mg PO daily. At 24 months of therapy, the patient developed a painful, red, and white striated oral lesion involving the left buccal mucosa and the adjacent buccal aspect of gingivae. Biopsy showed oral LDE. Causality assessment between osimertinib and the oral LDE via Naranjo Adverse Drug Reaction probability scale revealed a score of 5. MANAGEMENT AND OUTCOME: Osimetinib discontinuation was not felt to be in the best interest of the patient. Therefore, diphenhydramine HCL mouthwash every 6 h PRN (before meals) was started. Spicy and hot foods were discontinued. At a four-week follow-up visit, the patient reported moderate improvement in her symptoms. CONCLUSION: Oral LDEs are considered premalignant lesions as they can transform into squamous cell carcinoma; therefore, regular follow-up is needed. Awareness of this potential side effect of osimertinib would also prevent unnecessary (and potentially costly) work-up and lead to its prompt diagnosis and treatment.

Oral lichenoid lesions in two snuff users with contact allergy to carvone.

BACKGROUND: Contact allergy to the mint-tasting flavour carvone has been observed in patients with oral lichenoid lesions (OLL). Mint-flavoured products such as toothpaste frequently contain carvone. Snuff is a smokeless tobacco product that is chewed or placed in the mouth rather than smoked. In Sweden, the use of snuff and its flavoured versions is extremely common. OBJECTIVES: To investigate whether the consumption of mint-flavoured snuff is associated with contact allergy to carvone and subsequently plays a role in the aetiology of OLL. METHODS: Regarding the two patients, patch testing with snuff pouches was performed. High-performance liquid chromatography and gas chromatography-mass spectrometry analysis were used for identification of carvone in different snuff samples. RESULTS: Two patients with OLL were contacted allergic to carvone when patch tested. Both were using mint-flavoured snuffs several hours a day for many years. One patient was contacted allergic to the snuff pouch tested as is. Carvone was detected in the snuff samples of both patients. CONCLUSIONS: The patients were recommended to avoid the use of mint-flavoured snuffs, toothpaste and foodstuffs. At follow-up 3 months later, the patients had a dramatic clinical improvement of the OLL and oral symptoms. Exposure to mint-flavoured snuffs can be overlooked as a possible aggravating/provoking factor in OLL.

Clinical polymorphism of zoonotic cutaneous leishmaniasis: combination of the clinical and the parasitological diagnosis.

Zoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease caused by Leishmania (L.) major. This zoonosis is characterized by a broad-spectrum clinical polymorphism and may be underestimated and poorly treated since it is a simulator of various dermatoses. The aim of our study was to analyze the clinical polymorphism of patients with ZCL. A total of 142 patients with confirmed CL based on the microscopic examination of skin lesion biopsies were included in this study. Molecular typing of Leishmania species revealed that all patients were infected with L. major. In total, 14 clinical forms were observed. Six were typical and eight were atypical. The typical ZCL forms are grouped as follows: papular (26.76%), ulcero-crusted (26.05%), ulcerated (13.38%), impetiginous (9.86%), nodular (9.15%), and papulo-nodular (5.63%) lesions. In atypical ZCL forms, we described erythematous (2.81%), erysipeloid (1.4%), sporotrichoid, (1.4%), keratotic (0.7%) lupoid (0.7%), lichenoid (0.7%), psoriasiform (0.7%), and zosteriform (0.7%) lesions. Here, the lichenoid and the keratotic forms caused by L. major were reported for the first time in Tunisia. These findings will help physicians to be aware of the unusual lesions of ZCL that could be confused with other dermatological diseases. For this reason, it will be necessary to improve the diagnosis of CL especially in endemic areas. Such large clinical polymorphism caused by L. major may be the result of a complex association between the vector microbiota, the parasite, and the host immune state, and further studies should be carried out in order to reveal the mechanisms involved in clinical polymorphism of ZCL.

Immune checkpoint inhibitor-induced lichenoid drug eruption-sparing scar burns.

The authors present a striking case of a patient experiencing a lichenoid drug eruption secondary to immunotherapy, curiously sparing scarred skin from past burns. We observed vastly higher amounts of inflammatory lymphoid cells staining for PD-1; 70% in skin with a lichenoid drug reaction and 50% in scarred skin. The lack of a lichenoid reaction at sites of scarred skin may indicate that a basement membrane component may be causative for a lichenoid drug eruption.

Prevalence of and prognostic factors for Candida superinfection in oral lichen planus and lichenoid reactions: A retrospective cohort study.

BACKGROUND: Oral candidiasis occasionally occurs in patients with oral lichen planus (OLP) or lichenoid reaction (OLR). However, not all patients undergoing corticosteroid therapy develop Candida superinfection. Thus, the identification of prognostic risk factors may help to identify patients at risk of Candida superinfection. METHODS: A retrospective cohort study was conducted to review patients with OLP/OLR who received steroid therapy at a single dental hospital between January 2016 and December 2021. The prevalence of Candida superinfection and prognostic factors were assessed. RESULTS: Eighty-two eligible patients with OLP/OLR were retrospectively reviewed. The overall prevalence of Candida superinfection during the study period was 35.37%; the median time-to-event between initiation of corticosteroid therapy and diagnosis of superinfection was 60 days (interquartile range; 34-296). The ulcerative type of OLP/OLR, number of topical steroid applications, poor oral hygiene, and oral dryness were significantly associated with superinfection (p < 0.05; Fisher's Exact test) and were identified as prognostic factors in univariable risk ratio regression. Multivariable risk ratio regression revealed the ulcerative type of OLP/OLR and number of topical steroid applications were significant prognostic factors for Candida superinfection in patients with OLP/OLR. CONCLUSION: Candida superinfection occurs in approximately one-third of patients with OLP/OLR undergoing corticosteroid therapy. Patients with OLP/OLR should be closely monitored in the first 2 months (60 days; median time to infection) after steroid prescription. The ulcerative type of OLP/OLR and a higher number of topical steroid applications per day may represent prognostic factors to identify patients at risk of Candida superinfection.

Diagnostic utility of SOX10 immunostaining in benign lichenoid keratosis: A study of 21 cases.

BACKGROUND: Benign lichenoid keratosis (BLK) is a cutaneous lesion that can clinically mimic malignancy and may represent regression of a pre-existing lesion. BLK may show epidermal pseudo-nests prompting evaluation for a melanocytic lesion. False positivity of MART-1/Melan-A immunostaining in pseudonests has been showed; however, the value of SRY-related HMG-box 10 (SOX10) staining in BLK with features suspicious for a melanocytic proliferation has not been previously reported. METHODS: Twenty-one cases of BLK from 2015 to 2020 were identified. Slides were reviewed and SOX10 immunohistochemistry was performed on each case. Subsequently, Melan-A immunohistochemical staining was performed on all cases. RESULTS: In 10 cases (47.6%), unexpected SOX10 staining was seen in rare to numerous small, single cells in the epidermis above the basal cell layer. No malignancy was identified. Of the 10 cases, 8 (80%) showed suprabasal SOX10 staining did not show similar suprabasal Melan-A staining; 2 (20%) cases showed scattered suprabasal cells positive for Melan-A. CONCLUSION: SOX10 immunostaining in BLK can highlight scattered cells in the epidermis (not easily noticeable on routine stain). Performing SOX10 immunostain alone on BLK can prompt a misdiagnosis of a melanocytic lesion and should be done with caution.

PRAME immunohistochemistry can distinguish melanocytic pseudonests of lichenoid reactions from melanoma in situ.

BACKGROUND: Distinguishing melanocytic pseudonests encountered in lichenoid dermatoses or lichenoid keratoses from melanoma in situ (MIS) with brisk lichenoid inflammation can prove challenging. METHODS: We designed a case-control study to evaluate the accuracy metrics of PRAME immunohistochemistry to distinguish melanocytic pseudonests in lichenoid dermatoses or keratoses from inflamed MIS. Immunostaining for PRAME was performed on paraffin-embedded formalin-fixed diagnostic tissue using a rabbit monoclonal antibody to PRAME (Abcam), with a 1:3200 dilution on a Leica Bond detection system. RESULTS: Our search identified 21 cases of melanocytic pseudonests (n = 21, 46%) encountered in lichenoid dermatoses and 24 cases of inflamed MIS (n = 24, 53%). Each method of evaluating PRAME immunohistochemistry (PRAME+ clusters, PRAME % of melanocytes by four categories and PRAME+ melanocyte counts per linear mm of epidermal basal layer) showed statistically significant differences between the MIS and the pseudonest cohorts (respectively, p < 0.001; p < 0.001; and p < 0.001). Receiver operating characteristics analysis for PRAME+ melanocyte counts per linear mm of epidermal basal layer revealed an area under the curve of 0.9 ± 0.05 (95% confidence interval 0.9-1.0). When determining an optimal cut-off point for the best Youden index [sensitivity (%) + specificity (%) - 100], the cut-off of 1.0 PRAME+ melanocytes per linear mm showed a sensitivity of 79.2% and specificity of 85.7% (Youden index 0.65) to distinguish MIS from pseudonests. CONCLUSION: PRAME immunohistochemistry may constitute an additional tool for this challenging differential diagnosis.

Narrow-band imaging features of oral lichenoid conditions: A multicentre retrospective study.

OBJECTIVE: Narrow-band imaging (NBI), which highlights epithelial intrapapillary capillary loops (IPCLs) classified into five patterns (0 toIV) with increasing correlation to malignancy, has demonstrated effectiveness for detection of oral squamous cell carcinoma (OSCC). Lack of standardised procedures limits its use for routine inspection of oral lichenoid lesions including oral lichen planus (OLP), oral lichenoid lesion (OLL) and oral lichenoid reaction (OLR). The aim of this study was to analyse IPCL patterns of such lesions, assessing correlations with histopathological outcomes. MATERIALS AND METHODS: A multicentre, retrospective study was performed on 84 patients who underwent NBI and subsequent biopsy for suspected OLP/OLL/OLR. Patients were examined with Evis Exera III NBI system. Recorded NBI video endoscopies were evaluated to assess IPCL patterns and correlated with histopathological outcomes. RESULTS: No significant differences were detected among OLP/OLL/OLR on NBI inspection. All lichenoid lesions were significantly related to low-grade (0-II) IPCL patterns, clearly distinguishable from OSCC, showing pattern IV (p < 0.05). CONCLUSIONS: NBI cannot discern among OLP/OLL/OLR lesions. Interpretation should be modulated when assessing lichenoid lesions. NBI has potential to discern malignant transformation occurring in lichenoid lesions undergoing long-term follow-up, as IPCL pattern IV may be used as a clinical marker of malignancy arising in chronic inflammatory lesions.

Oral lichen planus and related lesions. What should we accept based on the available evidence?

Recent new terminologies have been proposed for lesions in the sphere of oral lichen planus (OLP) that theoretically present unique aetiological, clinical, prognostic or management characteristics different from those of the so-called typical forms of OLP. We aimed to critically analyse what concepts and terminologies related to OLP should we accept based on the available evidence. A review of the literature was carried out in order to critically analyse the concepts and terminologies related to OLP. New concepts and terminologies include oral lichenoid lesions; contact lichenoid reactions, drug lichenoid reactions or those in the context of graft-versus-host disease; chronic ulcerative stomatitis; lichen planus pemphigoid; and some lesions that are difficult to categorise, such as OLP with features of proliferative verrucous leukoplakia and lichenoid lesions of the upper labial mucosa. A multidisciplinary, multicontinent working group has recently published a guideline with recommendations for modifying definitions and terminologies associated with a disease, among which a reasoned, evidence-based justification for the proposed change is considered essential. An in-depth analysis of the newly proposed terms for OLP-related lesions shows that many of them are not justified. In this paper, we set out our position on the basis of the existing evidence on the appropriateness of the use of these new terms.

Group 1 and 3 innate lymphoid cells are increased in oral lichen planus and oral lichenoid lesions.

OBJECTIVES: Innate lymphoid cells (ILCs) are vital innate immune cells cooperating with T cells. While their phenotypes and functions in oral mucosa kept unclear yet. In the present study, the relative proportions and distribution of different ILC subsets in oral mucosa of oral lichen planus (OLP), oral lichenoid lesions (OLL), and controls were compared. SUBJECTS AND METHODS: Oral mucosal samples were collected from control (n = 29), OLP (n = 20), and OLL (n = 22) donors. ILCs subsets were characterized in single-cell suspensions by flow cytometry. Immunohistochemistry was performed to locate the CD127+ cells in situ. RESULTS: ILCs were present in healthy and increased infiltration in OLP/OLL (p = 0.0092, p = 0.0216). Infiltration of ILC1 increased in OLP/OLL mucosa (p = 0.0225, p = 0.0399), as did the infiltration of ILC3 increase in OLL mucosa (p = 0.0128). The ILC2/ILCs ratio was significantly reduced in OLP and OLL (p = 0.0124, p = 0.0346). CD127+ cells were mainly located closely at the basement membrane. CONCLUSIONS: The results of increased ILC1, decreased ILC2, and increased ILC3 suggested that changes of ILC distributions in oral mucosa may be relevant to persistent inflammation in local tissues, by promoting immune factors and weakening repair capacity.

Histopathology of oral lichen planus and oral lichenoid lesions: An exploratory cross-sectional study.

OBJECTIVE: To better characterize the histopathology of oral lichen planus and oral lichenoid lesions and to highlight the differences between them in order to support the clinician in the diagnostic and therapeutic management of such conditions. SUBJECTS AND METHODS: Fifty-five patients, clinically diagnosed with oral lichen planus (n = 25) or oral lichenoid lesions (n = 30), were consecutively enrolled in the present study. Subsequently, one blind pathologist reviewed all the biopsy specimens of enrolled subjects following a specific protocol to provide a detailed histopathological description. Demographic, anamnestic, and clinical data were also recorded from all the participants. Patients' data were analysed and compared using the chi-squared test, to provide distinguishing features between the studied conditions. RESULTS: We found a higher and statistically significant number of eosinophils in the oral lichenoid lesions compared with the oral lichen planus group (p < 0.01), an equally promising result was seen regarding plasma cells, which were more represented (p = 0.05) in the oral lichenoid lesions than in the oral lichen planus cases. No statistically significant differences were detected in demographic, anamnestic and clinical data. CONCLUSION: A mixed lichenoid inflammatory infiltrate, consisting of eosinophils and plasma cells, could be used as reliable histological features for the diagnosis of oral lichenoid lesions, as long as compared with findings obtained from the patients' history and clinical examination.

Tertiary lymphoid structures in oral lichen planus and oral epithelial dysplasia with lichenoid features: A comparative study.

OBJECTIVE: Tertiary lymphoid structures (TLSs) provide sites for antigen presentation and activation of lymphocytes, promoting their infiltration; thus, enhancing specific immune responses. The aim of this comparative cross-sectional study was to reveal the characteristics and influence of TLSs in oral lichen planus (OLP) and oral epithelial dysplasia (OED) with lichenoid features. METHODS: Clinical information and samples of 51 OLP and 19 OED with lichenoid features were collected. Immunohistochemistry was performed, and the structures where CD20+ B cells and CD3+ T cells aggregated with peripheral lymph node addressin positive (PNAd+) vessels were defined as TLSs. The results and clinical information were analysed. RESULT: TLS were found in 44 (86.3%) patients with OLP and 19 (100%) patients with OED. The TLS score was higher in OED group (p = 0.023), accompanied by an increased number of PNAd+ vessels. The TLS was significantly correlated with PNAd+ vessels (p = 0.027), CD20+ B (p < 0.001) and CD208+ dendritic cells (p = 0.001). Foxp3+ Treg cells but not CD8+ T cells infiltrated more severely in OED (p = 0.003) and increased when TLS score was high (p = 0.002). CONCLUSIONS: This study revealed the widespread development of TLSs in the OLP and OED. The presence of TLSs showed a close relationship with dysplasia and may increase malignant potency by over-inducing Treg cells.

Cytotoxic dermatitis: Review of the interface dermatitis pattern in veterinary skin diseases.

Interface dermatitis or lichenoid interface dermatitis refers to a cutaneous inflammatory pattern in which keratinocyte cell death is the essential feature. These terms have evolved from the originally described lichenoid tissue reaction. These lesions are the basis for an important group of skin diseases in animals and people where cytotoxic T-cell-mediated epidermal damage is a major pathomechanism. Yet, for largely historical reasons these commonly used morphological diagnostic terms do not reflect the essential nature of the lesion. An emphasis on subsidiary lesions, such as the presence of a lichenoid band, and definitions based on anatomical features, such as location at the dermo-epidermal location, may cause confusion and even misdiagnosis. This review covers historical aspects of the terminology, including the origin of terms such as "lichenoid." The types of cell death involved and the histopathologic lesions are described. Etiopathogenesis is discussed in terms of aberrations of immune/inflammatory mechanisms focusing on cutaneous lupus erythematosus, erythema multiforme, and Stevens-Johnson syndrome/toxic epidermal necrolysis. Mechanisms have most extensively been studied in humans and laboratory animals and the discussion is centered on these species. As interface dermatitis is firmly entrenched in dermatological parlance, rather than using "cytotoxic" as its substitute, the terminologies "interface cytotoxic dermatitis" and "panepidermal cytotoxic dermatitis" are recommended, based on location and extent of epithelium affected.

Lichenoid drug eruption associated with imatinib mesylate therapy.

INTRODUCTION: Imatinib Mesylate (IM), a tyrosine kinase inhibitor, has been reported to cause several adverse reactions, most of them with cutaneous involvement. Non- Lichenoid IM associated skin reactions have been sufficiently- recorded. To our knowledge, Lichenoid Drug Eruption (LDE) is recorded in a minority of registries. CASE REPORT: To describe an LDE induced case by IM treatment. TREATMENT AND OUTCOME: Histological Confirmation and promptly dermatological consultation relieved successfully the cutaneous adverse event. DISCUSSION: Ongoing expansion of IM usage in a wide spectrum of new indications is more likely to make physicians experience such LDE cutaneous side effects more often. Hence, they should be highly suspicious to early detect these distinct histologic entities, handle these undesired complications and guarantee satisfactory immediate outcomes, avoiding frivolous IM dosage modifications.

Use test with l-carvone in toothpaste on sensitized individuals.

BACKGROUND: The mint flavour carvone (l-carvone) is considered a weak contact allergen. However, contact allergy to carvone is more prevalent in patients with oral lichen planus or oral lichenoid lesions (OLP/OLL). OBJECTIVE: Our aim was to investigate how carvone affects sensitized individuals through a use test with toothpaste containing carvone. Non-flavoured toothpaste served as control. METHODS: Subjects were patch tested prior to the use test-14 subjects allergic to carvone (11 with OLP/OLL), 20 subjects with OLP/OLL and 3 healthy controls. The month-long use test comprised of using toothpaste twice daily. Subjects were examined fortnightly. Clinical signs were assessed with a mucosal scoring system. The subjects' oral health-related quality of life was measured with the oral health impact profile (OHIP-49). RESULTS: Local reactions to the carvone toothpaste presented as aggravated OLL (7/10) and peri-oral eczema (2/10) in allergic subjects. They also had significantly higher mucosal and OHIP scores compared with those receiving non-flavoured toothpaste. CONCLUSION: In sensitized individuals, oral exposure to carvone gives aggravated oral lesions and/or peri-oral eczema. The lesions mimic OLP and allergic individuals are therefore at risk of not being assessed with regard to flavour contact allergy.

Lichenoid lesions of the upper labial mucosa: a systematic review and a report of a new case with extensive follow-up.

OBJECTIVES: The paper reports the demographic characteristics of patients with lichenoid lesions affecting only the upper labial mucosa, with or without associated lesions in the maxillary anterior gingiva, alongside the lesions' clinical and histopathological features, treatment, follow-up and prognosis. Also, a new case with lengthy follow-up is presented. MATERIALS AND METHODS: A systematic review was performed in line with PRISMA guidelines. The literature search sources were PubMed, Scopus and Web of Science. RESULTS: In all, 26 patients (21 women, 5 men) were included in the review. 80.8% (n = 21) of the labial lesions were clinically erythematous and 19.2% (n = 5) were accompanied by white striations. The gingiva was affected in 46.2% of cases. All patients (100%, n = 24) reported symptoms. All of the lesions presented histological features of lichenoid inflammation. Granulomas were noted in 65.4% (n = 17) of the lesions. Topical corticosteroid was the most frequent therapy (89.5%, n = 17). CONCLUSIONS: Lichenoid lesions found solely in the upper labial mucosa, with or without adjacent gingival lesions, are rarely reported in the literature, and the reporting is often incomplete. A definitive aetiology could not be established for the lesions. Likewise, there is little information about this condition's long-term prognosis.

Oral mucosal toxicities induced by immune checkpoint inhibitors: Clinical features and algorithm management.

Immune checkpoint inhibitors (ICIs) have emerged as standard therapies for an increasing number of advanced cancers. Nonspecific immune activation may lead to immune-related adverse events among which dermatological reactions are one of the most prevalent (all-grade incidence ranging from 30 to 60%). Oral mucosal adverse reactions to ICIs are far less common than cutaneous adverse events. However, a spectrum of oral changes with characteristic features has recently emerged, including lichenoid reactions, sicca syndrome, and even autoimmune bullous disorders with oral involvement. Oral changes mainly occur during the first year of treatment, often concurrently with other dermatological changes, and may involve up to 10% of patients under ICI therapies. This article provides a systematic review of the oral changes reported with these therapies based on a rich iconography.