Week 7- Oral Lichen Planus Flashcards
What are examples of oral lichenoid reactions?
- Oral lichen planus
- Oral lichen planus associated with underlying disease
- Lichenoid contact reactions
- Drug-induced lichenoid reactions
- Graft vs host
What is characteristic of oral lichenoid reactions and lupous erythematous?
Acquired lesions that can’t be scraped off and have a specific pattern
What is lichen planus?
Chronic inflammatory disease affecting skin and mucous membrane. Oral lesions may present alone or with concomitant skin lesions.
Describe prevalence of OLP
- 4th decade of life
- Affects women more frequently
- Affects 1-2% of population
How can lichen planus present clinically?
- Reticular
- Papular
- Plaque-like
- Erosive
- Atrophic
- Bullous
What are the common sites of oral lichen planus?
- Buccal mucosa
- Tongue
- Gingiva
Describe skin lesions from lichen planus
- Violaceous flat-topped papules on ankles, wrist and genitalia
- Facial skin is spared
- Nail deformities
- Alopecia
What are lichen planus lip lesions often confused with?
Actinic cheilitis
What is desquamative gingivitis and its clinical presentation?
Erythema extends beyond the marginal gingiva, involving the full width of the gingiva and sometimes the alveolar mucosa
- Erythematous gingiva
- Desquamation and erosion of gingival epithelium
- Blister formation
What conditions is desquamative gingivitis common in?
- Lichen planus
- Pemphigoid
- Pemphigus
- Dermatitis herpetiformis
What is the pathogenesis of Lichen Planus?
T-cell mediated autoimmune disease in which the auto-cytotoxic CD8 + T cells trigger apoptosis of the basal cells of the oral epithelium.
What virus may be considered an etiological factor in OLP?
Hep C virus
What is the difference between CD4 and CD8 T cells?
- CD4 T cells are the helper T cells, which assist other blood cells to produce an immune response,
- CD8 T cells are the cytotoxic T cells that induce cell death either by lysis or apoptosis
What are essential features for LP histopathology?
- ‘Liquefaction degeneration’ in basal cell layer
- Well-defined band of T cells in superficial connective tissue
- Absence of dysplasia
What are non essential features of LP?
- ‘Saw tooth’ rete ridge configuration
- Parakeratosis
- Civatte bodies
- Separation of epithelium from lamina propria due to basal cell destruction
What are civattte bodies?
Remnant of necrotic basal cells
What is the pathognomonic clinical appearance of LP?
Interlacing white reticular striae on bilateral posterior buccal mucosa
What are DD for LP?
- Frictional keratosis
- Oral lichenoid reaction
- Oral leukoplakia
- Lupus erythematosus
- Pemphigus
- Mucous membrane pemphigoid
- Erythematous candidiasis
What should you do to confirm diagnosis of LP?
Biopsy for histopathological confirmation
How are lichenoid drug reactions diagnosed?
- Unilateral and accompanied by hx of new drug intake
- Most reliable diagnostic aid is to observe rx resolving on drug withdrawal and returning when patient re-challenged
What drugs are associated with lichenoid drug reactions?
- Anti-hypertensives
- Anti-diabetic
- Anti-thyroid
- Anti-malarials
- NSAIDs
What are dental restorative material induced lichenoid reactions usually caused by & where do they appear?
Usually caused by amalgam and are confined to areas of oral mucosa in close proximity
What does biopsy reveal about dental restorative material induced lichenoid reaction?
Diffuse lymphocytic infiltrate rather than subepithelial band
What are characteristics of lupus erythematosis?
- Resemble LP but are less symmetrically distributed
- Keratotic striae of LE are more delicate and show characteristic radiation from central focus
