Oral metronidazole treatment of lichen planus

Metronidazole may display anti-inflammatory features in periodontitis treatment: A scoping review

AIM

Metronidazole (MTZ) is an antimicrobial agent used to treat anaerobic infections. It has been hypothesized that MTZ may also have anti-inflammatory properties, but the evidence is limited and has not been previously reviewed. Thus, this scoping review aimed to answer the following question: "What is the evidence supporting anti-inflammatory properties of metronidazole that are not mediated by its antimicrobial effects?"

METHODS

A scoping review was conducted according to the PRISMA-ScR statement. Five databases were searched up to January 2023 for studies evaluating the anti-inflammatory properties of MTZ used as monotherapy for treating infectious and inflammatory diseases.

RESULTS

A total of 719 records were identified, and 27 studies (21 in vivo and 6 in vitro) were included. The studies reported experimental evidence of MTZ anti-inflammatory effects on (1) innate immunity (barrier permeability, leukocyte adhesion, immune cell populations), (2) acquired immunity (lymphocyte proliferation, T-cell function, cytokine profile), and (3) wound healing/resolution of inflammation.

CONCLUSION

Taken together, this scoping review supported a potential anti-inflammatory effect of MTZ in periodontitis treatment. We recommend that future clinical studies should be conducted to evaluate specific MTZ anti-inflammatory pathways in the treatment of periodontitis.

Lichen Planus: What is New in Diagnosis and Treatment?

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

Systemic non-steroidal immunomodulators for oral lichen planus treatment-a scoping review

OBJECTIVE

The aim of this scoping review was to evaluate the efficacy and safety of the use of systemic nonsteroidal immunomodulators (SNSI) for oral lichen planus (OLP) treatment.

MATERIALS AND METHODS

This review was conducted according to PRISMA-ScR guidelines and registered at PROSPERO (CRD42021243524). Consulted databases were Pubmed, Embase, Scopus, and Web of Science. The inclusion criteria was as follows: clinical trials, case series, prospective, and retrospective studies conducted with participants presenting OLP of any sex and age.

RESULTS

Thirty-two studies were selected, assessing 9 different SNSI: methotrexate, dapsone, levamisole, hydroxychloroquine, thalidomide, metronidazole, azathioprine, mycophenolate mofetil, and colchicine. Methotrexate and dapsone were the drugs with the best evidence among the options included, regarding number and quality of studies. Methotrexate resulted in significant improvement in the clinical condition and remission of symptoms, ranging between 63 and 93% of cases. Dapsone presented a similar effect to the use of topical corticosteroids and tacrolimus CONCLUSION: Among SNSI therapeutic options, methotrexate, and dapsone showed promising efficacy and safety. However, large-scale randomized clinical trials are still needed.

CLINICAL RELEVANCE

SNSI have been used in the treatment of recalcitrant OLP; however, so far, it is not clear which are the best options. This scoping review highlights the potential use of methotrexate and dapsone.

A retrospective cohort study of the efficacy of metronidazole in oral lichen planus

Lichen planus (LP) is an inflammatory dermatosis with mucosal variants, including oral LP (OLP). OLP has a relapsing chronic course and may significantly affect a patient's quality of life. We analysed the efficacy of metronidazole as a treatment for OLP via a retrospective chart review of patients with a diagnosis of OLP seen at our institution over 10 years. Thirty patients with OLP were treated with metronidazole 500 mg twice daily. Most patients (n = 18; 60%) showed improvement with metronidazole, including 10 (33%) who experienced complete resolution of symptoms. Our results were limited by the retrospective nature of the review and the relatively small cohort size. Given the efficacy, mild side-effect profile and the less immunosuppressive nature of metronidazole vs. alternative systemic treatment options, metronidazole is a reasonable option to try in patients with symptomatic OLP who have failed topical treatment options.

Pediatric lichen planus: A single-center retrospective review of 26 patients with follow up

BACKGROUND/OBJECTIVES

Pediatric lichen planus (LP) is rare with variable prevalence and atypical presentations compared to adults. Data on LP are lacking for the pediatric population in the United States. We present demographics, presentations, and treatments for a pediatric LP cohort.

METHODS

We reviewed 26 patients diagnosed with LP at 20 years or younger. Treatment responses were defined as no response, partial response, and complete response.

RESULTS

Demographics included 54% females and median diagnosis age of 16 years (range 6-20). Most patients presented with cutaneous LP (65%), with fewer having associated oral (23%), nail (7.7%), or genital (3.8%) involvement. Some had cutaneous-only LP (38%) or strictly mucosal LP (oral-only 19% and genital-only 15%). LP lesions were pruritic (50%), painful (19%), and/or asymptomatic (35%). Complete/partial responses occurred with medium-potency topical corticosteroids in cutaneous (n = 7; 64%), oral (n = 3; 75%), and genital LP (n = 3; 100%), with high/ultra-high potency topical corticosteroids in oral LP (n = 6; 86%), and with topical calcineurin inhibitors in genital LP (n = 2; 100%). Side effects were clobetasol-related oral candidiasis and biopsy-related penile depressed scar. Most patients with available follow-up achieved remission (n = 17; 81%).

CONCLUSIONS

Pediatric LP usually presents in adolescence with cutaneous involvement and is symptomatic. However, patients frequently can have oral, genital, or nail lesions or may be asymptomatic, so they need thorough examinations and follow-up. Long-term remission is common due to treatment or natural disease course. Medium-potency corticosteroids are recommended for cutaneous, oral, and genital LP. Various other local and systemic therapies exist with successful treatment responses.

Cutaneous Immune-Related Adverse Events (irAEs) to Immune Checkpoint Inhibitors: A Dermatology Perspective on Management [Formula: see text]

Immune checkpoint inhibitors have proven to be efficacious for a broad spectrum of solid organ malignancies. These monoclonal antibodies lead to cytotoxic T-cell activation and subsequent elimination of cancer cells. However, they can also lead to immune intolerance and immune-related adverse event (irAEs) that are new and specific to these therapies. Cutaneous irAEs are the most common, arising in up to 34% of patients on PD-1 inhibitors and 43% to 45% on CTLA-4 inhibitors. The most common skin manifestations include maculopapular eruption, pruritus, and vitiligo-like lesions. A grading system has been proposed, which guides management of cutaneous manifestations based on the percent body surface area (BSA) involved. Cutaneous irAEs may prompt clinicians to reduce drug doses, add systemic steroids to the regiment, and/or discontinue lifesaving immunotherapy. Thus, the goal is for early identification and concurrent management to minimize treatment interruptions. We emphasize here that the severity of the reaction should not be graded based on BSA involvement alone, but rather on the nature of the primary cutaneous pathology. For instance, maculopapular eruptions rarely affect <30% BSA and can often be managed conservatively with skin-directed therapies, while Stevens-Johnson syndrome (SJS) affecting even 5% BSA should be managed aggressively and the immunotherapy should be discontinued at once. There is limited literature available on the management of the cutaneous irAEs and most studies present anecdotal evidence. We review the management strategies and provide recommendations for psoriatic, immunobullous, maculopapular, lichenoid, acantholytic eruptions, vitiligo, alopecias, vasculitides, SJS/toxic epidermal necrolysis, and other related skin toxicities.

Potential association between Fusobacterium nucleatum enrichment on oral mucosal surface and oral lichen planus

OBJECTIVE

We determined the bacterial community structure of the buccal mucosa in patients with oral lichen planus (OLP) and evaluated the potential association of Fusobacterium nucleatum with OLP.

SUBJECTS AND METHODS

We collected buccal mucosal swab samples of patients with OLP (n = 20) and healthy controls (n = 10) and performed 16S rRNA gene sequencing and real-time PCR to determine potentially different bacteria. Damaged and adjacent non-damaged mucosal swab samples of 25 OLP patients were used to detect the amount of F. nucleatum by real-time PCR.

RESULTS

Compared with healthy controls, enrichment of Fusobacterium and Granulicatella was more abundant in patients with OLP (p = .0146 and 0.0034). The abundance of Fusobacterium and F. nucleatum was significantly enriched on buccal mucosa of patients with OLP compared with healthy controls (p = .0043 and 0.0235). Compared with adjacent non-damaged buccal mucosa of OLP patients, the amount of F. nucleatum in the damaged mucosa was significantly increased (p = .001). We examined third-level KEGG pathways for bacteria on mucosal surface and found that genes controlling sporulation and ether lipid metabolism were enriched in patients with OLP.

CONCLUSIONS

A high amount of F. nucleatum may be associated with OLP. Further studies are required to investigate the precise association of F. nucleatum with OLP.

Crucial Role of Microbiota in Experimental Psoriasis Revealed by a Gnotobiotic Mouse Model

Psoriatic patients have altered microbiota, both in the intestine and on the skin. It is not clear, however, whether this is a cause or consequence of the disease. In this study, using an experimental mouse model of psoriasis induced by imiquimod (IMQ), we show that oral treatment with a broad spectrum of antibiotics (MIX) or metronidazole (MET) alone mitigates the severity of skin inflammation through downregulation of Th17 immune response in conventional mice. Since some antibiotics, including MET, can influence immune system reactivity, we also evaluated the effect of MIX in the same model under germ-free (GF) conditions. GF mice treated with MET did not show milder signs of imiquimod-induced skin inflammation (IISI) which supports the conclusion that the therapeutic effect is mediated by changes in microbiota composition. Moreover, compared to controls, mice treated with MIX had a significantly higher abundance of the genus Lactobacillus in the intestine and on the skin. Mice treated with MET had a significantly higher abundance of the genera Bifidobacterium and Enterococcus both on the skin and in the intestine and of Parabacteroides distasonis in the intestine. Additionally, GF mice and mice monocolonized with either Lactobacillus plantarum or segmented filamentous bacteria (SFB) were more resistant to IISI than conventional mice. Interestingly, compared to GF mice, IMQ induced a higher degree of systemic Th17 activation in mice monocolonized with SFB but not with L. plantarum. The present findings provide evidence that intestinal and skin microbiota directly regulates IISI and emphasizes the importance of microbiota in the pathogenesis of psoriasis.

Erosive diseases of the vulva

Vesicobullous and inflammatory diseases produce vulvar erosions that may exhibit nonspecific morphology and represent a diagnostic challenge. An approach to arriving at the correct diagnosis is presented. Most common etiologies are reviewed.

Two case reports of cutaneous adverse reactions following hepatitis B vaccine: lichen planus and granuloma annulare

We report two cases of adverse cutaneous reactions following hepatitis B vaccination. The first case occurred 3 weeks after the first dose of hepatitis B vaccine in a 16-year-old white girl with the onset of lichen planus lesions on her thighs and abdomen. After the second dose a disseminated lichen planus developed within 2 weeks. The second case concerns to the development of papular and patch granuloma annulare in a 58-year-old white woman 2 months after the second dose of hepatitis B vaccine. To the best of our knowledge, only a few paediatric and adult cases of lichen planus as a complication of hepatitis B vaccination have been reported in medical literature so far. This is the second case of granuloma annulare following hepatitis B vaccine. Our report, similar to earlier papers, appears to support the onset of lichen planus and granuloma annulare as a possible rare complication of hepatitis B immunization.

Oral lichen planus part II: therapy and malignant transformation

Oral lichen planus lesions can cause discomfort, pain, and a burning sensation. Therefore, all professionals who deal with the oral cavity must be aware of all the therapeutic options for it. This article presents a review of the literature on oral lichen planus, focusing on its treatment, and also discusses the important and controversial potential for the evolution of oral lichen planus into epidermoid carcinoma.

Diagnosis and therapy of anogenital lichen planus

Genital lichen planus is a fairly common disease of genital skin that exhibits a widely variable morphology. Lichen planus occurring on the mucosal surfaces is chronic, and most often erosive and painful, frequently producing debilitating scarring. Mild, non-erosive disease is controllable with topical corticosteroids. Although erosive disease is much more difficult to manage, the use of topical corticosteroids, sometimes in combination with other topical or systemic medications, maximizes comfort and preserves function, especially with careful attention to local care and secondary infection.

Position Paper: Oral Features of Mucocutaneous Disorders

Part of periodontology involves the diagnosis and treatment of a variety of non-plaque-related diseases of the periodontium. The International Workshop for a Classification of Periodontal Diseases and Conditions noted that the periodontist may be called upon to manage non-plaque-related mucocutaneous disorders either alone, or as part of a treatment team consisting of physicians, dentists or other allied health care professionals. This informational paper will review the etiology, clinical manifestations, diagnosis, and treatment of the most common chronic mucocutaneous diseases, including those that may present as desquamative gingivitis or intraoral vesiculobullous lesions. This paper is intended for the use of periodontists and other members of the dental profession.