Lichen Planus

Question 1

summary of lichen planus

Answer 1

chronic disease
mainly affecting age 30-50
skin cases 50% oral lesions
oral cases 10-30% skin lesions
can be idiopathic / drug related / systemic disease related

Question 2

reticular lichen planus

Answer 2

lacy pattern of white lines across mucosa

Question 3

atrophic / erosive lichen planus

Answer 3

background of erythematous change is atrophy of mucosa and where this is the predominant feature this is termed atrophic lichen planus
When there is no epithelium at all it is ulcerative / erosive lichen planus
Yellow fibrous covering over the base of the connective tissue
treat symptoms not appearance

Question 4

what is lichen planus (histologically)

Answer 4

clear T cell infiltrate into basement membrane of connective tissue; this lymphocytic band hugging the basement membrane is a key diagnostic feature of lichen planus
can also see:
orthokeratosis
wedge shaped hyper granulosis
civatte bodies (dead keratinocytes)
dermal epidermal junction obscured by lymphocytes
vacuoles at basal layer
thick band of lymphocytes under epidermis
langerhans cells also involved

Question 5

lichenoid reaction (histologically)

Answer 5

chronic inflammatory cell infiltrate
saw tooth rete ridges
basal cell damage
patchy acanthosis
parakeratosis

Question 6

causes of LP

Answer 6

not caused by one single thing but rather a multitude of things being presented to the langerhans cells & this is the end pathway
- lymphocytic activation
- attempt to remove chronic irritation, overreaction to ‘normal’ triggers
- virus implicated in immune upregulation but NOT as a cause of LP i.e. hep C / herpes
- sometimes external triggers i.e. medicines, amalgam restorations
other causes thought to include:
genetic predisposition, physical / emotional stress, injury to skin, localised skin disease such as herpes zoster, systemic viral infection, contact allergy, drugs

Question 7

symptoms

Answer 7

often none
may relate to thinning of epithelium so can be sensitive to hot/spicy food or having burning sensation in mucosa
up to 50% pt have other areas in body involved which can be before, during or after oral lesions i.e. skin, scalp, genital, hair, nails

Question 8

oral LP sites

Answer 8

buccal mucosa
gingiva (desquamative gingivitis)
tongue - lateral aspect, dorsum
lips
palate

Question 9

buccal LP

Answer 9

commonest site
anywhere on BM - anterior at commissure, mid, posterior around 3rd molar tooth
most common site for incidental finding & easy biopsy site

Question 10

gingival LP

Answer 10

can be found in isolation often termed desquamative gingivitis
- similar clinical appearance to gingival pemphigoid and to plasma cell gingivitis so histology tells the difference
- can give very erythematous appearance to gingivae which concerns pt

Atrophic lichen planus equivalent on the gingiva
Disease of gum skin covering and not affecting bone or supporting structures so no teeth should be directly lost

Ptx who struggle with plaque control will have more troublesome gingival lichen planus

Question 11

appearance & management of gingival LP

Answer 11

can be very patchy
some forms more typical reticular pattern seen
OH v important in settling lesion esp interdental, seems plaque driven in most pt

Erythematous band extends the whole way around the upper teeth
No marginal gingivitis
Changes in gingiva are consistent with those higher up in the attached gingiva
Desquamative gingivitis appearance

Question 12

why can biopsy be difficult for gingival lesions

Answer 12

• risk of damaging attachment area of gingiva/tooth
• adherent attached mucosa damaged lifting from bone
  take care deciding to biopsy gingival lesions

difficult to biopsy attached gingiva as can be hard to remove without damaging and to remove from underlying periosteum & must be wary about causing damage to the junctional tissue supporting the tooth
Should only be carried out when there is a good clear margin of gingiva between the tooth and the lesion and ideally taken from high in the sulcus

Question 13

tongue LP

Answer 13

• dorsum usually idiopathic; loss of papillae & smooth tongue surface
• lateral aspect may have drug / amalgam tigger; amalgam most likely if there is an isolated lateral tongue lesion but look at tongue at rest to see if there is an amalgam contact
• easy biopsy site but painful when healing

Question 14

contributing factors to LP

Answer 14

most are idiopathic so no known cause
some related to medication esp hypertensives
some related to amalgam

Question 15

common medications that can cause LP

Answer 15

ACE inhibitors
beta blockers
diuretics
NSAIDs
DMARDs i.e. sulphasalazine

Question 16

lichenoid drug reaction

Answer 16

more often widespread lesions
often bilateral & mirrored
often poorly responsive to standard steroid tx

Question 17

managing lichenoid drug reactions

Answer 17

must consider:
- benefit of drug
- risk of stopping drug
(does the benefit of stopping the medical drug outweigh the risk to the pt health; for mild lichen this is unlikely but for significant lichen it is probable where maximum topical/systemic tx likely needed to control symptoms)
- discomfort from symptoms
if in doubt discuss with GP i.e. easy change from ACE inhibitor to AT2 blocker which has same effect on BP not is not seen to be associated with lichenoid reaction

Question 18

management of amalgam related lichen lesion

Answer 18

if not symptomatic do you consider doing nothing
potentially malignant lesion although LP has very low malignant transformative risk
replacing restoration will increase tooth damage
cost to pt
no routine need for other amalgams to be replaced
consider crown / composite

Question 19

LP management overall

Answer 19

remove any cause i.e. medicine / amalgam restoration
biopsy unless good reason not to
blood tests - haematinics, FBC
if lupus suspected then antibody screen (ANA, Ro, dsDNA)

Question 20

for mild intermittent lesions

Answer 20

topical OTC remedies i.e. CHX mw / benzdamine mw
avoid SLS containing toothpaste i.e. sensodyne pronamel & kingfisher

Question 21

for persisting symptomatic lesions in primary care setting

Answer 21

topical steroids (as for mouth ulcers)
- beclomethasone MDI 0.5mg/puff for 2 puffs 2-3x daily
- betamethasone rinse - 1mg/10ml 2mins x2 daily

Question 22

for persisting symptomatic lesions in hospital setting

Answer 22

higher strength steroids (puffer/rinse)
skin steroid cream - clobetasol
can be applied in a veneer in gingival lesions
topical tacrolimus - ointment / mw
hydroxychloroquine
systemic immunomodulators - azathioprine, mycophenolate

Question 23

what must be considered in palatal lesions

Answer 23

lupus must always be considered
Discoid lupus is a solitary lesion found in the oral mucosa where there is association with systemic autoantibodies and systemic lupus erythematosus

Question 24

histology of lupus erythematosis

Answer 24

atrophic epithelium
basal vascular damage
melanophage
intense lymphocytic infiltrate - is much deeper in the connective tissue and away from the basement membrane - important distinction found in biopsy

Question 25

GVHD

Answer 25

graft v host disease i.e. after bone marrow transplant / stem cell transplant

Question 26

why are lichen like lesions important

Answer 26

underlying disease needs consideration as it could be GVHD / lupus
if only oral symptoms treat symptomatically as LP
liaise with physician regarding oral lesions

Question 27

lupus lesions can be (2)

Answer 27

1. only in the mouth (discoid lupus - no antibodies)
2. mouth & elsewhere (systemic lupus - ANA/Ro/dsDNA antibodies in the blood