lichen planus overview

Question 1

What is the prevalence of lichen planus?

Answer 1

Affects 1% of the population
Mainly in age 30-50
Where skin cases are found, 50% contain oral lesions

Question 2

What happens histologically in lichen planus?

Answer 2

T cells infiltrate into the basal layer of connective tissue

Question 3

Give 4 histological signs of lichenoid reactions

Answer 3

Any from:
- chronic inflammatory cell infiltrate
- saw tooth rete ridges
- basal cell damage
- patchy acanthosis of epithelial layer
- parakeratosis of superficial epithelium

Question 4

What causes the clinical changes in lichen planus?

Answer 4

Lymphocyte activation deals with perceived threat
Langerhans cells in epithelium present an antigen which activates the immune response
An attempt to remove chronic irritation may cause changes to epithelium and clinical changes seen

Question 5

How may viruses be involved in lichen planus and how are they involved?

Answer 5

Eg include hep C and HSV
Viruses can be implicated in immune up-regulation during lichen planus but do not cause it

Question 6

Give 2 examples of external triggers that may cause lichenoid reactions?

Answer 6

Medicines eg - antihypertensives
Amalgam restorations

Question 7

What can cause exacerbation of lichen planus symptoms?

Answer 7

Physical and emotional stress

Question 8

Give examples of 4 drugs that can cause a lichenoid reaction

Answer 8

Gold
Quinine
Beta blockers
ACE inhibitors

Question 9

What is koebnerisation?

Answer 9

Lichen planus appearing as an isomorphic response to where the skin has been scratched or after surgery

Question 10

Describe cutaneous lichen planus

Answer 10

Found around the wrists, white surface with striae (Wickham’s striae)
A reticular pattern

Question 11

Name 6 different appearance types of lichen planus

Answer 11

Reticular
Atrophic
Papular
Erosive
Plaque like
Bullous

Question 12

What are the symptoms of oral lichen planus?

Answer 12

Often none
Sensitivity to hot and spicy foods
Burning sensation in the mucosa - thinning of epithelium caused by atrophy changes from lichen planus

Question 13

What are the oral lichen planus sites?

Answer 13

Buccal mucosa (most common)
Gingivae - if gingivae alone then termed desquamative gingivitis
Tongue - lateral aspect and dorsum
Lips
Palate

Question 14

Describe buccal lichen planus

Answer 14

Commonest site
Can be found anywhere on the buccal mucosa
Most common site for asymptomatic or incidental finding
Easy biopsy site

Question 15

Describe desquamative gingivitis?

Answer 15

Similar appearance to gingival pemphigoid and to plasma cell gingivitis
Gives erythematous appearance to gingivae
Can be patchy
OH very important in settling lesion
Biopsy can be difficult for gingival lesions
Patient may have no symptoms

Question 16

What makes a gingival biopsy difficult and how should it be carried out?

Answer 16

Risk of damaging attachment area of the gingivae/tooth
Adherent attached mucosa damaged from lifting bone
Biopsy ideally taken from high in the sulcus

Question 17

Describe tongue lichen planus

Answer 17

Dorsum usually idiopathic - loss of papillae and smooth surface
Lateral may have a drug or amalgam trigger
Easy biopsy site but painful when healing

Question 18

Describe lip lichen planus and how it is managed

Answer 18

Difficult to manage
Appearance may be reticular but can also be erythematous and crusty
Needs biopsied
Managed by regular sunblock and topical medicament for lichenoid change