What is oral lichen planus and what causes its development?

Oral Lichen Planus: Etiology and Development

Oral lichen planus (OLP) is a chronic inflammatory autoimmune condition affecting the oral mucosa, primarily caused by T cell-mediated cytotoxicity, where auto-cytotoxic CD8+ T cells trigger apoptosis of oral epithelial cells. 1, 2

Clinical Presentation

• Presents with characteristic features:

  • White lacy patterns (reticular form)
  • Erythematous and erosive lesions (symptomatic forms)
  • Violaceous papules and plaques
  • Possible erosions and striae in oral mucosa 1

• Common symptoms:

  • Significant pain and burning sensation
  • Discomfort during eating, drinking, and oral hygiene
  • Reduced quality of life 3

Etiopathogenesis

OLP develops through a complex immunological process involving:

• Primary mechanism: T cell-mediated autoimmune response where CD8+ T cells target and destroy oral epithelial cells 2

• Contributing factors:

  • Stress
  • Genetic predisposition
  • Certain medications
  • Dental materials
  • Systemic diseases
  • Poor oral hygiene 4

• Pathological process:

  • Activation of CD8+ T lymphocytes
  • Involvement of mast cells
  • Expression of intercellular adhesion molecule-1 (ICAM-1)
  • Expression of major histocompatibility complex class II antigens
  • Vacuolar degeneration and lysis of basal cells
  • Liquefaction of the basal layer 4

Diagnosis

• Clinical examination: Characteristic white lacy patterns, erythematous areas, or erosions on oral mucosa 1

• Histopathological confirmation:

  • Zone of cellular infiltrate (mainly CD8+ cells) in the superficial layer of connective tissue
  • Signs of liquefaction degeneration of the basal membrane 3
  • Biopsy recommended to confirm diagnosis and exclude dysplasia or malignancy 2

• Differential diagnosis:

  • Oral leukoplakia
  • Lichenoid drug reactions
  • Contact dermatitis
  • Mucous membrane pemphigoid
  • Candidiasis 1

Management Approaches

First-Line Treatment

• Topical high-potency corticosteroids:

  • Clobetasol propionate 0.05% gel (preferred)
  • Fluocinonide 0.05% gel (alternative)
  • Applied directly to lesions 2-3 times daily, especially after meals and before sleep 1

• Important considerations:

  • Antifungal prophylaxis (e.g., miconazole) should be considered with prolonged steroid use
  • Monitor for side effects including oral candidiasis, bad taste, nausea, dry mouth 1, 5

Alternative Therapies for Refractory Cases

• Topical calcineurin inhibitors:

  • Tacrolimus 0.1% ointment
  • Pimecrolimus 1% cream
  • Useful for patients who cannot tolerate corticosteroids 1

• Photodynamic therapy (PDT):

  • Emerging as a promising alternative treatment
  • Uses photosensitizers activated by specific wavelength light
  • Studies show improvement comparable to conventional treatments
  • Minimal side effects (slight burning sensation during activation) 3, 6

• Other options:

  • Retinoids (synthetic and natural analogues)
  • Hyaluronic acid
  • Aloe vera
  • Intralesional corticosteroid injections for resistant areas 1, 5

Long-term Considerations

• Disease course:

  • OLP is chronic and rarely undergoes spontaneous remission
  • Requires long-term management and monitoring 2

• Malignant potential:

  • Small risk of developing squamous cell carcinoma
  • Persistent ulcerations should be biopsied
  • Regular follow-up recommended every 6-12 months for well-controlled disease 1

• Quality of life impact:

  • Address pain management
  • Consider impact on eating, drinking, and oral hygiene
  • Psychological support may be beneficial 3

Important Clinical Caveat

Unlike cutaneous lichen planus which often resolves spontaneously within 1-2 years, oral lichen planus tends to be more persistent and resistant to treatment, requiring long-term management strategies and regular monitoring for potential malignant transformation 1.