Lichen Planus

Question 1

Clinical features of oral lichenoid reaction

Answer 1

acquired white lesion with specific pattern that cannot be scraped off

Question 2

Clinical features of classic oral LP

Answer 2

acquired white lesion with specific pattern that cannot be scraped off, bilateral and in multiple sites

Question 3

What is lichen planus?

Age/gender, WHERE is it commonly seen intraorally (3) Where else can it present and how do they appear? (2)

Answer 3

chronic, inflammatory disease affecting skin and mucosal membrane

women (4:1) in 40s

buccal mucosa, tongue and gingiva

skin on ankles, wrist, genitalia (not facial skin) -> purplish pink violaceous flat-topped papules
(and rarely lips - can be confused for actinic cheilitis)

Question 4

5 types of LP presentations in buccal mucosa(described in pics)

Which of these is most dangerous?

Answer 4

papular
reticular
erosive-ulcerative (most dangerous)
bullous

Question 5

What kind of gingival lesion seen with OLP?

Description

Where else is this seen?

Answer 5

desquamative gingivitis

erythematous gingiva, desquamataion and erosion of gingival eptihelium and blister formation

also seen in pemphigus vulgaris, mucous membrane pemphigoid, bullous pemphigoid, hep c, leukaemia etc

Question 6

pathogenesis of LP

Answer 6

T-cell mediated autoimmune disease

auto-cytotoxic CD8+ T cells trigger apoptosis of basal cells of oral epithelium

Question 7

LP histopathological features (essential vs non-essential)

Answer 7

liquefaction degeneration in basal cell layer
normal epithelial maturation pattern -> absence of epithelial dysplasia
well-defined band like zone of cellular infiltration confined to superficial part of CT

saw tooth rete ridges
civatte bodies

Question 8

IF OLP shows dysplasia in biopsy what does it become

Answer 8

OPMD

Question 9

Pathognomonic appearance (specific to this disease) of LP

Answer 9

interlacing white reticular striae on bilateral posterior buccal mucosa

Question 10

Diff Dx of LP

Answer 10

frictional keratosis 
oral lichenoid reaction
oral leukoplakia 
erythemtaous candidosis 
lupus erythematous 
pemphigus vulgaris 
phemphygoid

Question 11

How to differentiate LP from its common diff dx

Answer 11

Drug induced lichenoid reaction (usually unilateral and newly started drug) best diagnostic method is to observe reaction to drug withdrawal
e.g. antihypertensives, antidiabetic, antimalarials, NSAIDs, antithyroid

Dental material induced lichenoid reaction: usually amalgam