lichen planus overview Flashcards
activity of disease
chronic
times of disease activity and disease quiescence (although there may still be visible lichenoid change inside the mouth they may have no symptoms)
Can be idiopathic or drug related, occasionally systemic disease
who gets lichen planus
age mainly 30-50
lesions often last between 10-15 years
skin cases - 50% chance oral lesions too
oral cases - chance 10-30% skin lesions too
Can be idiopathic or drug related, occasionally systemic disease
3 typical appearance classes for lichen planus
reticular
atrophic/erosive
ulcerative
but also get:
* plaque
* papular
* bullus
* desquamatous gingivitis
reticular lichen planus appearance
Lacy pattern of white lines running across the mucosa (background of normal mucosa or of erythematous change mucosa)
atrophic/erosive lichen planus appearance
Erythematous background – atrophic;
* extended to the point of having no epithelium at all (ulceration expected), but see a yellow-firbous covering over the base of connective tissue
* associated with malignant transformation
Can appear extensive – suspect to be painful
* But symptoms vary person to person and are often mitigated by fibrous covering on top of connective tissue
ID type of lichen planus
ulcerative
what to do when tx lichen planus
Treat the pt symptoms but not the appearance of the lesion (lesion cannot be cured by intervention
what is lichen planus
T cell infiltrate into the basement membrane area of the connective tissue
Lymphocytic band hugging the basement membrane is one the key diagnostic features of lichen planus
5 histological characteristic of lichenoid reactions
Chronic Inflammatory cell infiltrate
Saw tooth rete ridges
Basal cell damage
Patchy acanthosis
Parakeratosis
under high mag can see dead keratinocytes (Civatte bodies)
what does the histological findings of lichenoid reactions tell us
Lymphocyte activation – likely responding to perceived threat, Langerhans cells in epithelium presenting an antigen that activates the immune responses
Attempt to remove chronic irritation, causes change in epithelium and clinical appearance
Final common pathway of immune activation
* can have many different causes/triggers presenting to Langerhans cells causing T lymphocytes
Overreaction to ‘normal’ triggers
* ? Virus implicated in immune upregulation but NOT as a cause of LP
(if Hepatitis C, herpes virus found the LP becomes more troublesome)
* Sometimes external triggers - Medicines; Amalgam restorations
7 possible causes of LP
Genetic predisposition cannot be specifically HLA linked, more common in families
Physical and emotional stress – more troublesome
Injury to the skin; lichen planus often appears where the skin has been scratched or after surgery — this is called the isomorphic response (koebnerisation)
Localised skin disease such as herpes zoster—isotopic response
Systemic viral infection, such as hepatitis C (which might modify self-antigens on the surface of basal keratinocytes)
Contact allergy, such as to metal fillings in oral lichen planus
Drugs; gold, quinine, b-bloakcers, ace inhibitors can cause a lichenoid rash
Contact area in the centre – likely due to amalgam restoration, radiation of lichenoid pattern from that
lichen planus elsewhere
Up to 50% patients have other areas of the body involved
* Can be before, during or after oral lesions
* Skin, scalp, genital, hair and nails
Dentist should be aware of skin aspects of LP
raised purple lesions around wrists – typical, Wickham’s Striae (can be used to term reticular lesions in mouth), itchy
trauma due to scratching
scalp – can cause hair loss
nails – characteristic ridging
symptoms of lichen planus
Often none
* Incidental finding in routine exam
May relate to thinning of epithelium
* Sensitive to hot/spicy food
* Burning sensation in the mucosa
Related to thinning of epithelium caused by the atrophic changes from Lichen Planus
5 possible oral sites for LP
Buccal mucosa (commonest)
Gingivae (Desquamative Gingivitis – on gingivae alone)
Tongue – lateral aspect, dorsum
Lips
Palate
buccal lichen planus
Commonest site
Anywhere on BM
* Anterior at commissure
* mid
* Posterior around 3rd molar tooth
* Most common site for incidental finding (asymp)
Easy biopsy site
gingival lichen planus
Can be found in isolation
Often then termed desquamative gingivitis
* Similar clinical appearance to gingival pemphigoid and to plasma cell gingivitis (LP most common of 3)
* Only histology tells the difference
Can give very erythematous appearance to the gingivae
* Concerns the patient (usually have very few other symptoms) - Atrophic lichenoid reaction on gums
* Worried it is ‘gum disease’ and teeth will fall out
Reassure the pt, disease of gum skin covering and not affecting bone or supporting structures so thus no teeth should be directly lost through gingival LP
Can be very patchy
Some forms more ‘typical’ reticular pattern is seen
ORAL HYGIENE very important in settling lesion
Especially interdental
Seems PLAQUE DRIVEN in many patients - Association between gingival LP and plaque – cause more troublesome LP
Biopsy can be difficult for gingival lesions
* Risk of damaging the attachment area of the gingiva/tooth
TAKE CARE DECIDING TO BIOPSY GINGIVAL LESIONS
Only when there is a good clear margin of gingival tissue between the tooth and the lesion and ideally high in the sulcus
tongue lichen planus
Dorsum usually idiopathic
* Loss of papillae and smooth tongue surface (shiny), asymp
Lateral aspect may have drug/amalgam trigger
* Amalgam most likely if there is an ISOLATED lateral tongue lesion
* Look at tongue position at REST to see if there is amalgam contact
Easy biopsy site but PAINFUL when healing (buccal mucosa preferable if lesions in both)
lip lichen planus
hard to manage
Appearance maybe simple reticular changes or more erythematosus and crusty appearance
Need to rule out
* Actinic damage
* Dysplasia
Management
* Regular use of SPF
* Topical medicament for lichenoid change
describe
Dense thickening – biopsy key to rule out dysplasia and is just hyperkeratosis
Many forms of LP present at once on dorsum of tongue
describe
Lateral tongue – white hyperkeratotic change, thickening of keratin on surface of LP
describe
Ulcerative change – potentially in contact with amalgam
