OD 32 - Lichen planus and lichenoid lesions

Question 1

What is the definition of oral lichen planus?

Answer 1

Chronic inflammatory disorder of stratified squamous epithelium (hyperkeratosis)
White papules coalesce to form white lines

Question 2

What are the clinical features of oral lichen planus?

Answer 2

Bilateral
White or red
Most common areas = posterior buccal mucosa
Followed by tongue, gingiva labial mucosa, lower lip (everything else uncommon)

Question 3

What are the types of white and red oral lichen planus?

Answer 3

White - papular, reticular, plaque-like

Red

• Atrophic –> erythematous lesions causing desquamative gingivitis, involve dorsum of tongue, discomfort
• Erosive –> ulcerative, intense pain and burning
• Bullous –> blisters

Question 4

What are some extra oral manifestations of lichen planus?

Answer 4

Usually several months after skin lesions, severity doesn’t correlate to oral
Minor itching and lesions usually on wrists/forearms
Most frequent E/O for female is vulvovaginal
Planopilaris - involving scalp and hair follicles, causing scarring alopecia and nail striations

Question 5

What is the pathogenesis of oral lichen planus?

Answer 5

T mediated autoimmune disease
TNF-a and IFN-y produced
OLP lesional T cells don’t secrete IL4, IL10, TGF-B

Question 6

What is the aetiology of oral lichen planus?

Answer 6

Genetics - patients have higher levels of TNF-a and IFN-y 
Dental materials - mainly amalgam 
Virus' (Hep C)
Drugs - B-blockers/NSAIDs
Trauma and stress

Question 7

What is the malignant transformation of oral lichen planus?

Answer 7

Premalignant lesion
0.4%-0.5% turn to malignancy
Increased in reticular plaque/ atrophic-erosive OLP
Overexpression of p53 protein in OLP malignant transformation