Manifestations of Oral Lichen Planus

The American Academy of Oral and Maxillofacial Pathology (AAOMP) recognizes six forms of oral lichen planus (OLP). The white forms — reticular, papular, and plaque-like lesions — are typically asymptomatic, while the red forms — atrophic, erosive, and bullous lesions — are usually symptomatic.^1,2 The reticular type is the most common.³

Reticular OLP is clinically identified by its pathognomonic feature of a lattice-like white thickening called Wickham striae. Reticular OLP is primarily bilateral, located on the buccal mucosa, and sensitive to spicy foods.^1,4-6 All OLP lesions may present with nontypical variations, therefore this may make clinical assessment and diagnosis difficult when the lesion is not clearly identifiable by the above features.⁷

We present examples of atypical manifestations — discovered and verified at Midwestern University College of Dental Medicine in Glendale, Arizona — to assist dental practitioners in clinical diagnosis of these variations.

Asymptomatic, Asymmetric Manifestation

Patient #1, an otherwise healthy middle-aged woman of Indian descent, presented with an asymptomatic, asymmetric manifestation with a single circular papule on the left buccal mucosa (Figure 1 and 2) and an asymptomatic diffuse, thickened, melanotic pigmented striae on the right buccal mucosa (Figure 3).

Diffuse White Striae on the Mandibular Gingiva

Patient #2, an otherwise healthy middle-aged woman of Chinese descent, had diffuse white striae on the mandibular gingiva with burning symptoms (Figure 4).

Asymptomatic Oral Plaques

Patient #3, an older male with a complex medical history presented with asymptomatic oral plaques on the dorsum of the tongue (Figure 5).

Differential Diagnosis and Biopsy

The differential diagnosis for OLP is candidiasis, leukoplakia, oral squamous cell carcinoma (OSCC), and allergic contact stomatitis.⁶  Though OLP has traditionally been considered benign, prompt biopsy of all unilateral or bilateral suspected OLP- lichenoid type lesions is advised. Without biopsy, OLP may mask an underlying leukoplakic or lichenoid dysplasia.⁸

The malignant potential of OLP-OSCC remains under debate.²  Studies report conflicting malignancy rates ranging from 0% to 12.5%.^1,2 Recent literature reports transformation rates for malignancy as low as 0.44% to 1.0%, but with smoking, alcohol, or a more aggressive erosive subtype of OLP, this number could be higher.^9,10

Tongue OLP lesions are more likely to progress to OSCC.¹ Because the OLP lesions may never resolve, even with treatment, they should be closely monitored after biopsy, especially erosive OLP forms, which have the highest OSCC transformation rate.^1,3,11 Another study indicated that OLP-OSCC malignancy has a 40% recurrence rate.¹⁰

Oral lichenoid contact hypersensitivity may be caused by mucosal contact allergies to flavoring agents such as cinnamon, resins, and metals, including gold, mercury, copper, and nickel.^1,11,12

In patient #1, Figure 3, a potential gold allergy on the right mucosa is suspected because the lesion is in direct contact to a gold crown on tooth #30. If allergy is suspected, the patient should be referred to an allergist for an allergy patch testing. The Keobner phenomenon is an isomorphic response in which new lesions arise along lines where trauma or scratching occurs, especially seen in cutaneous lesions.⁵ The Keobner phenomenon indicates disease, warranting tissue biopsy.⁷ In the oral cavity, this response may appear when OLP- lichenoid lesions develop on the buccal mucosa or tongue due to mechanical trauma of cheek biting, rough surfaces of fractured teeth or dental restorations, or oral habits.⁹ Removing the suspected causative agent, such as the gold crown in Figure 3 or a localized irritant, is recommended to see if the lesion resolves.¹

Treatment Options

OLP is a chronic disease that may resolve with treatment.^5,13 Topical clobetasol or triamcinolone corticosteroid creams are traditional treatments. OLP responds well to steroid mouthrinses but their use carries a risk of developing oral candida.^7,9,14

Tacrolimus is a nonsteroidal cream prescribed for severe or refractory OLP.^14,15 Caution should be used with this medication because there have been reports of conversion of OLP to OSCC. If the patient must be on this medication, then close monitoring and frequent biopsies are recommended.¹⁵

If topical treatment proves insufficient, then systemic immunosuppressive agents, such as methotrexate or hydroxychloroquine, may be alternatives to discuss with the primary care physician.¹⁶ Nonmedication adjunct treatment options with low level lasers of 9300 nm CO₂ laser or 940 nm diode laser may be successful in alleviating inflammation and discomfort, especially in erosive OLP.^17,18

Research has also found that in the erosive form of OLP, the natural protective nature of antioxidants in the saliva is much lower than normal and may account for the increased risks for cancerous transformation and infections.^1,7 Patients with the erosive form of OLP are at a higher risk for yeast, bacterial, or viral infections⁶ and may need additional treatment such as antifungal medications or referral to physician.

Possible Etiologies

Although OLP has been studied since the mid-1800s, the disease still has no clear etiology and its pathophysiology is not fully understood.^1,7 Recent research points to potential causative processes of an antigen-specific Type IV hypersensitivity reaction mediated by T-cells, a second nonspecific mechanism of pro-inflammatory mediators and cytokines from mast cells activation and/or autoimmune responses.^1,5,9

The AAOMP has defined the criteria in histopathological identification of OLP as “a band-like zone of predominately lymphocytic infiltrate in the epithelium-lamina propria interface, liquefactive degeneration in the basal cell layer, lymphocytic exocytosis, and the absence of epithelial dysplasia and verrucous epithelial architectural changes.”^1,2

The destruction of the basal epithelium results in alteration of the rete ridges, giving a “saw-tooth” appearance.^5,6 The histologic features in Figure 1 exemplifies this type of diagnosis of OLP for the single, atypical circular lesion in Patient #1, Figure 2.

Bilateral Presentation

OLP is primarily bilateral, but can be symptomatic or asymptomatic, and symmetrical or asymmetrical. Unilateral lesions are considered atypical. Up to 90% of lesions are located on the buccal mucosa, but can occur on the gingiva and tongue.¹ The atypical manifestations in Figures 2 through 5 highlight these variations of location.

The highest prevalence of OLP is seen in women in their 50s to 70s.^1,3,9,11 Though OLP is not considered to have specific racial predilection, some studies are now showing that African-Americans and those of Arabian and Indian descent may be at higher risk.⁵ Patients of color may have increased atypical melanotic pigmentation as is seen in the right buccal mucosa in Figure 3.¹⁹

Atrophic or erosive red forms of OLP are the most often associated with burning pain and can be symptomatic, especially to spicy foods.^1,5 Approximately two-thirds of OLP lesions cause burning pain such as with the striae lesions on the buccal gingiva in patient #2 (Figure 4).⁹ Eliminating potential oral irritants, such as oral care products containing sodium laurel sulfate, spices, or flavoring agents, may be helpful.

With atypical lesions, diagnosis may be difficult. Premalignant OLP lesions may have dysplasia, but visually may appear similar to benign lesions.^2,8,10 It is essential to monitor and follow up on all OLP lesions at every appointment after a histopathologic diagnosis. A complete oral cancer examination is recommended along with oral photography and a periodontal probe measurement to document changes in size (Figures 2 and 4).

The patient should be questioned on changes in symptoms or flareups with spicy foods or other agents. Repeated biopsies may be required for OLP lesions with erosive tendencies, any noted clinical changes, history of OLP-OSCC, or additional risk factors (eg, poor oral hygiene, malnutrition, smoking or alcohol use, which increase the risk for oncological transformation of cells).^1,6,10

Patient Education

Patient education is crucial so they understand the uniqueness of this pathology. Up to 15% of patients with OLP may develop purplish cutaneous papules on the wrist, scalp, forearms, and trunk.^1,5,7,11 Others develop genital, gastrointestinal, and conjunctival mucosal lesions, requiring referral.^1,5,7 Autoimmune diseases, such as lupus erythematosus, Sjögren syndrome, and alopecia areata, have also been associated with OLP.^1,20 The rate of occurrence of OLP is 2.5 to 4.5 times more likely in patients with the hepatitis C virus.^5,6 Though results vary, the acute erosive form of OLP has shown to have a correlation with hepatitis C and may involve interprofessional coordination of care.²¹

The AAOMP criteria also recognize another variation, oral lichenoid drug-induced reactions (OLL), which may occur with nonsteroidal anti-inflammatory medications; antihypertensives, such as beta-blockers, thiazide diuretics, and antirheumatics; antimalarials; and antiretrovirals. These medications have been shown to initiate or exacerbate existing OLP.^1,5,11 OLL may resolve if the causative medication agent is removed. Interestingly, lesions were reported to rarely reoccur after drug rechallenging.⁵

Oral Systemic Link

Wang et al²² recently reported a correlation between diabetes, thyroid disease with low levels of hormone, and OLP. Patients on diabetes medications along with high blood pressure medications often have atypical OLP lesions on the tongue such as in Patient #3 (Figure 5).^23,24 Some studies categorize lichen planus as a psychosomatic disease, with higher frequency when stress, anxiety, or depression is present.^1,7,25

Along with frequent examinations, oral health professionals should refer patients to their primary care team to be tested frequently for these comorbidities.²² Dentists may want to provide dietary counseling, review the risks of transformations to oral cancers — especially for atypical lesions, offer referrals for potential cutaneous involvement, provide smoking cessation counseling, and administer human papillomavirus vaccinations.⁶

Given the potential for underlying medical conditions or involvement of other organs, dentists should collaborate with primary care physicians, gynecologists, ophthalmologists, and dermatologists for interprofessional assessment and care when OLP is suspected or diagnosed.^6,9

Conclusion

OLP lesions offer a wide variety of clinical variations that complicate diagnosis. A thorough medication and medical history, interprofessional coordination, and biopsy are key to successful diagnosis and treatment. Though the transformation rate is low, oral health professionals must be aware of the need to biopsy, treat, and monitor for malignancy in OLP lesions.

References

1. Rotaru DI, Sofineti D, Bolboaca SD, Bulboaca AE. Diagnostic criteria of oral lichen planus: A narrative review. Acta Clin Croat. 2020;59:513-522.
2. Cheng YS, Gould A, Kurago Z, Fantasia J, Muller S. Diagnosis of oral lichen planus: a position paper of the American Academy of Oral and Maxillofacial Pathology. Oral Surg Oral Med Oral Pathol Oral Radiol. 2016;122:332-354.
3. Liu J, Xu H, Tang G, et al. A multi-center cross-sectional study of 1495 Chinese oral lichen planus patients. Oral Dis. 2024;30:3155-3164.
4. Papageorgiou C, Apalla Z, Lazaridou E, et al. Atypical case of lichen planus recognized by dermoscopy. Dermatol Pract Concept. 2016;6:39-42.
5. Arnold DL, Krishnamurthy K. Lichen planus. Available at ncbi.nlm.nih.gov/books/NBK526126/. Accessed October 8, 2024.
6. Gall R, Navarro-Fernandez IN. Lichen planus erosive form. Available at ncbi.nlm.nih.gov/books/NBK560700/. Accessed October 8, 2024.
7. GururaJ N, Hasinidevi P, Janani V, Divynadaniel T. Diagnosis and management of oral lichen planus — review. J Oral Maxillofac Pathol. 2021;25:383-393.
8. Fatahzadeh M, Rinaggio J, Chiodo T. Squamous cell carcinoma arising in an oral lichenoid lesion. J Am Den Assoc. 2004;135:754-759.
9. RaJ G, RaJ M. Oral lichen planus. Available at ncbi.nlm.nih.gov/books/NBK578201/. Accessed October 9, 2024.
10. Sagheb K, Blatt S, Rahimi-Nedjat RK, et al. Oral squamous cell carcinomas developing from oral lichen planus: A 5-21 year retrospective study. J Maxillofac Oral Surg. 2022;21:1088-1095.
11. Krupaa RJ, Sankari SL, Masthan KM, Rajesh E. Oral lichen planus: An overview. J Pharm Bioallied Sci. 2015;7(Suppl 1):S158-61.
12. Ahlgren C, Bruze M, Moller H, et al. Contact allergy to gold in patients with oral lichen lesions. Acta Derm Venereol. 2012;92:138-143.
13. Gulzar MA, Gul N, Alvi FD, et al. Comparison of photodynamic therapy and corticosteroid therapy in management of oral lichen planus: A systematic review of randomized controlled trials. Photodiagn Photodyn. 2023;44:103747
14. Sandhu S, Klein BA, Al-Hadlaq M, et al. Oral lichen planus: comparative efficacy and treatment costs-a systematic review. BMC Oral Health. 2022;22:161.
15. Mattsson U, Magnusson B, Jontell M. Squamous cell carcinoma in a patient with oral lichen planus treated with topical application of tacrolimus. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;110:e19-25.
16. Chirravur P, Sroussi H, Treister N, et al. Hydroxychloroquine for the management of recalcitrant oral lichen planus. Oral Surg Oral Med Oral Pathol Oral Radiol. 2024;137:355-361.
17. Schuster G, Roberts E. The clinical impact of 9300nm CO₂ laser low energy ablation therapy on oral lichen planus: a case report. J Laser Dent. 2022;26:111–122.
18. Misra N, Chittoria N, Umapathy D, Misra P. Efficacy of diode laser in the management of oral lichen planus. BMJ Case Rep. 2013;2013:bcr2012007609.
19. Da Silva Barros Y, De Carla Batista Dos Santos V, Das Neves Barbosa Sena MS, et al. Pigmented oral lichen planus: A case report. Oral Surg Oral Med Oral Pathol. 2020;130:e187.
20. Chung PI, Hwang CY, Chen YJ, et al. Autoimmune comorbid diseases associated with lichen planus: a nationwide case-control study. J Eur Acad Dermatol Venereol. 2015;29:1570-1575.
21. Gheorghe C, Mihai L, Parlatescu I, Tovaru S. Association of oral lichen planus with chronic C hepatitis. Review of the data in literature. Maedica (Bucur). 2014;9:98-103.
22. Wang Y, Han X, Zhu L, Shen Z, Liu W. Possible interplay of diabetes mellitus and thyroid diseases in oral lichen planus: A pooled prevalence analysis. J Dent Sci. 2024;19:626-630.
23. Smitha C, Shergill S, Jain S, Saxena D, Pandav G, Bansal P. Grinspan syndrome. Advances in Human Biology. 2024;14(1):83-85.
24. Goyal L, Gupta ND, Gupta N. Grinspan syndrome with periodontitis: Coincidence or correlation? J Indian Soc Periodontol. 2018;22:263-265.
25. Kalkur C, Sattur AP, Guttal KS. Role of depression, anxiety and stress in patients with oral lichen planus: A pilot study. Indian J Dermatol. 2015;60:445-459.

From Decisions in Dentistry. October/November 2024;10(6):42-45.