Lichen Planus Flashcards
What is lichen planus?
Chronic, inflammatory mucocutaneous disease of unknown aetiology
What is the likely aetiology of lichen planus?
Cell mediated immunological reaction within affected tissues due to an unknown trigger
Epidemiology of lichen planus
Common (0.5-2% of adult population)
Female predilection 2:1
Age of onset around 30-60
Why is lichen planus likely to be a cell mediated immunological reaction?
There is an accumulation of T cells within the epithelium along with macrophages, langerhans cells and local production of cytokines
Why is lichen planus likely to be an autoimmune disease?
Females > males and it is associated with other AI diseases e.g. primary billary cirrhosis
What type of lichen planus has a known HLA association?
VVG variant (vulvovaginal-gingival)
What are the cutaneous features of lichen planus?
4 Ps - polygonal, purititc, purple papules commonly found on the flexors of the wrists, lumbar region, anterior leg (shins) and genitalia
What are the features of the vulvovaginal gingival variant of lichen planus?
Lesions affecting the vulva, vagina and gingiva
Scarring type is associated with lacrimal duct scarring, perforated eat drugs, hoarse voice and difficulty swallowing
How long do cutaneous LP lesions last?
Around 2 years (shorter duration than oral LP)
What are the phenotypes of oral lichen planus?
- Reticular
- Papular
- Erosive
- Atrophic
- Plaque type
- Bullous
List the oral features of lichen planus
Bilateral, symmetrical lesions commonly on the buccal mucosa, labial mucosa, dorsal tongue, gingiva Striations Papules Atrophic areas Erosions Plaques
What are striations?
Sharply defined and white
May appear lacy, starry or annular
Can be firmer than the surrounding mucosa
What are papules?
Pinpoint, flat topped papules (can be white, red or purple) which may be interspersed with the striate
Describe atrophic lichen planus lesions
Red areas of mucosal thinning, may be associated with striate
Describe erosion lichen planus lesions
Shallow and irregular areas of epithelial destruction which may be covered in a slightly raised, yellow fibrin layer
Margins may be depressed due to fibrosis and healing at the periphery
Describe plaque-like lichen planus lesions
Dense thickening of the mucosal tissue (tends to be white)
What % of oral LP have it confined to the gingiva only?
10%
What is oral postinflammatory hyperpigmentation?
Brown or black pigmentation of the mucosa following the lichenoid lesion distribution as a result of an inflammatory response
Describe the disease course of lichen planus
Periods of relapse and remission
What type of lichen planus is more persistent?
Plaque like lesions
Common CO for lichen planus
- Slight stiffness of mucosa
- Soreness or oral discomfort (esp with atrophic or erosive types) - difficult to eat
- May be asymptomatic due to insidious onset
Describe oral lichen planus that is confined to the gingiva only
Lesions tend to be atrophic and the gingiva is shiny, inflamed and smooth (desquamative)
Straie are uncommon
Plaque accumulation present due to difficulty cleaning
Histological signs of lichen planus
- Compact, dense band of lymphocytic infiltrate under the epithelio-mesenchymal junction, or partially disrupting the epithelium
- Saw tooth profile and rete ridges
- Hyperkeratosis and acanthosis
- Apoptotic body (liquefaction degradation)
- Widening of basement membrane
- Melanin drop outs
Special IX for lichen planus
- Biopsy for histopatholology
- Immunoflouresence to rule out mmp, pv and dle
Management pathway for lichen planus
- Diagnosis
- Supportive - not infectious
- Topical agents +/- systemic depending on severity
- Maintainence
- Monitoring
What topical agents are used for lichen planus
Difflam or lidocaine
What topical therapies are used for lichen planus
Corticosteroids**, fluticasone, mometasone or calcineurin inhibitors
What systemic therapies are used for lichen planus
Corticosteroids***, hydroquinone, azathioprine or methotrexate
Treatment of gingval lichen planus
- Difficult
- Triamcinolone paste (corticosteroid)
- Tacrolimus mouthwash if unresponsive
Differential diagnosis of oral lichen planus
- Lichenoid reaction
- Frictional keratosis
- Leukoplakia
- If erythematous LP then erythematous candidiasis
- Lupus
- Pemphius and MMP
Referral for oral lichen planus
- Unsure of diagnosis
- Speckled lesion - suspicious
- Unresponsive to steroids
What is the oral disease severity score?
Categories OLP as mild, moderate and severe based on site score, activity score and pain score
What type of OLP tends to have the highest severity score?
Ulcerative oral lichen planus
What are oral lichenoid lesions?
Lichen-planus like lesions that are caused wither by systemic drug treatment, or those where the histological picture is not diagnostic for LP
Describe the clinical appearance of oral lichenoid lesions due to amalgam
- Small, unilateral lesions localised around amalgam restorations
Describe the clinical appearance of oral lichenoid lesions due to drug therapy
- Widespread lesions in the mouth and skin associated with the onset of a drug
- Asymmetrical
What drugs are associated with oral lichenoid lesions
- Colloidal golds
- Antihypertensives
- Oral hypoglyceamics
- NSAIDs - naproxen
- Penecillamine
- Tricyclic antidepressants
- Antimalarials
- Biologics
What dental materials are associated with oral lichenoid lesions
Amalgam, composite, acrylic, cobalt and nickel
Describe the pathology of OLL due to dental materials
Contact hypersensitivity (delayed = type IV) due to alteration in antigenicity of basal keratinocytes by the release of dental materials
When is the diagnosis ‘oral lichenoid lesion’ made?
- Histopathology not diagnostic of lichen planus
- Histopathology is diagnostic of OLP but clinically doesn’t match
- Clinical and histology indicates OLL
What is the malignant potential of oral lichen planus
Reports suggest 1-4% change over 10 years (however this is controversial and may be considered as <1%)
List risk factors for increased risk of malignant change in OLP lesions
- Smokers
- Females
- Lesions on the tongue
- Atypical lesions
- Red lesions
What is desquamative gingivitis?
A clinical description of erythematous gingiva, desquamation and erosion of the gingival epithelium and blister formation - usually affecting whole width of the attached gingiva around teeth
What is desquamative gingivitis associated with?
- Lichen planus (most common)
- MMP
- Pemphigus vulgaris
