Oral Lichen Planus Overview

Oral Lichen Planus

• Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous condition, potentially lifelong.
• It's characterized by periods of remission and exacerbation.
• Etiology remains unknown.
• More common in middle-aged adults over 40, and more prevalent in women.

Lichen Planus: Concept

• Described by Wilson in 1869.
• An inflammatory mucocutaneous condition.
• Possibly a lifelong disease.
• Characterized by remissions and exacerbations.
• Affects middle-aged adults over 40.
• More common in women.
• Skin manifestations: pruritic, violaceous papules and plaques.
• Scalp manifestations: pruritic papules and atrophic scarring with patchy hair loss.
• Nail manifestations: subungual hyperkeratosis, anonychia.
• Mucosa manifestations: genital and oral (60%).

Epidemiology

• Lichen Planus prevalence: <1%
• Oral Lichen Planus prevalence: 1-2%
• No racial predilection.
• Male/Female ratio (♂/♀): 1/4
• Age range: 40-70 years

Pathogenesis

• Unknown etiology.
• A T-cell mediated disease.
• Altered cell-mediated immunity, triggered by endogenous or exogenous factors.
• Results in an altered response to autoantigens.
• This altered immune response leads to keratinocyte apoptosis (cell death) in the basal layer.
• Predisposing factors:
  • Psychological factors (anxiety, depression)
  • Hepatitis C virus
  • Dental restoration materials
  • Certain drugs

Pathogenesis (con't) - HCV Infection

• Relationship between OLP and HCV is unstable, with prevalence varying from 0% to over 60% in patients, depending on the study.
• High rates observed in Japan, Italy, and Brazil.
• It's uncommon to diagnose HCV positivity in OLP patients, but OLP is seen in individuals known to be HCV carriers.

Clinical Features

• OLP patients may also have skin lesions (15%).
• OLP lesions are typically white or gray streaks forming linear or reticular patterns.
• Lesions are generally multiple, bilateral, but not always symmetrical.
• Locations: buccal mucosa, tongue, gingiva, lower lip (most common). Palate, floor of mouth, and upper lip are also affected uncommonly.
• Clinical forms: reticular, erythematous (atrophic), erosive (ulcerated), plaque-like, papular, bullous —severity varies.
  • Reticular is the most common (characterized by fine white lines - Wickham striae).
  • Atrophic presents with diffuse red lesions with white striae, surrounded by erythematous areas; varying degrees of discomfort.
  • Erosive is the most serious form, with central irregular ulcerations, and variable number of sores/ulcers; surrounded by fine, keratinized striae with a network appearance.
  • Desquamative gingivitis is characterized by erythematous or ulcerated areas in the attached gingiva, with small whitish areas.

Clinical Features (con't) - Patient Demographics

• 205 patients with OLP study:
  • 89.7% had buccal mucosa lesions.
  • 50.2% had tongue lesions.
  • 27.3% had gingival lesions.

Diagnosis

• Diagnosis relies on clinical and histopathological examinations.
• OLP diagnosis might be questioned in cases of unilateral location, isolated lesions, or lack of bilateral lesions within the buccal mucosa.
• Typical lesions: white lines (Wickham's striae) in an erythematous area, sometimes with erosive lesions, bilateral, and more or less symmetrical pattern; commonly found in buccal mucosa, gingiva, and tongue.
• OLP typically has a chronic course, with remissions and exacerbations.

Histopathological Aspects

• Classical findings:
  • Liquefactive degeneration (hydropic degeneration) of the basal layer.
  • Band-like dense inflammatory infiltrate of T lymphocytes.
  • Normal epithelial maturation.
  • Hyperkeratosis (orthokeratosis or parakeratosis).
• Direct immunofluorescence: fibrinogen deposits in the basement membrane in an irregular pattern.

Differential Diagnosis

• Differential diagnoses rely on lesion morphology:
  • Cheek biting
  • Leukoplakia
  • White sponge nevus
  • Candidiasis
  • Aphthae
  • Pemphigus vulgaris
  • Pemphigoid

Malignization

• The potential for malignancy in OLP remains controversial.
• Studies show malignancy frequency ranging from 0% to 5.3%, depending on the follow-up period (6 months to 20 years).
• Lack of objective and unanimous criteria for diagnosis poses a challenge in studying potential malignancy.

Treatment

• Treatment focuses on symptom relief and minimizing disease impact, individualizing care for each patient.
• No single treatment fits all cases due to unknown cause.
• Oral hygiene is critical, especially with gingival lesions. Teeth, fillings, and dentures should be polished.
• Exclusive reticular lesions (asymptomatic) often require no treatment.
• Medical treatments usually target atrophic, erosive, or symptomatic OLP.
• Corticosteroids (locally applied or systemically given).
  • Topical ointments/mouthwashes for localized lesions.
  • Oral steroid rinses for generalized lesions.
  • Perilesional steroid injections, particularly for persistent erosions.
• If no response to topical therapy, tacrolimus mouth rinse (immunosuppressant) may be used for generalized atrophic or erosive lesions. For severe cases, systemic corticosteroids (prednisone) may be necessary.

Oral Lichenoid Lesions

• Some cases might be caused by:
  • Dental restorative materials (especially amalgam and gold)
  • Drugs (e.g., NSAIDs, antihypertensives, antidiabetics, antimalarials) and others
  • Chronic graft-versus-host disease (bone marrow transplant recipients).
• Associated drugs: Many other medications, as the list may not be complete.
• Predisposing factors should be carefully evaluated and, when appropriate, corrected, for example, dental amalgams should be removed in some cases. Consideration of removal or substitution of the medication may be necessary.

This quiz covers the characteristics, history, and epidemiology of Oral Lichen Planus (OLP), a chronic inflammatory condition. Learn about its prevalence, demographics, and the skin, scalp, and nail manifestations associated with this disease. Understand the etiology and pathogenesis, which remain largely unknown.