Lichen planus Flashcards
What is lichen planus?
A chronic inflammatory immune mediated disease that affects the oral mucosa and skin
What is the most histological signs that is considered to be a diagnostic feature of lichen planus?
T-cell infilitrate into the basement membrane under the epidermis?
Other than a hugging band of lymphocytes at the basement membrane, Give 3 other histological signs of lichen planus?
- Orthokeratosis
- Civatte bodies
- Vacuoles at basal layer
What is the aetiology of lichen planus?
- Langerhans cells present an antigen that activates an immune response leading to t-cells attacking the body tissue
What are 4 triggers of lichen planus other than allergy to metals and drugs?
- Genetics
- Physical and emotional stress
- Injury to the skin
- Viral infections - herpes zoster and Hep C
If lichen planus occurs as a response of an injury to skin, what do we call this response?
isomorphic
If lichen planus occurs as a response of a localised skin disease such as herpes zoster, what do we call this response?
isotopic
What 2 group of drugs might trigger lichen planus?
- beta-blockers
- Ace inhibitors
What are the symptoms of lichen planus ?
- Often none
- sensitivity to hot and spice food
- Burning sensation in the mucosa
Other than the oral mucosa , give 4 areas which can be affected by lichen planus?
- Skin
- Scalp
- Genitals
- Hair and nails
What 4 sites in the oral mucosa that can be affected by lichen planus?
- buccal mucosa
- gingivae
- tongue
- lips
What is the commonest site for lichen planus in the oral mucosa?
buccal mucosa - at commissure , middle , around 3rd molar
What term can describe gingival lichen planus?
Desquamative gingivitis
If lichen planus affect the dorsum of the tongue, what might your clinical findings be? 2
- Loss of papilla
- Smooth tongue surface
If the lateral aspect of the tongue is affected by lichen planus by an isolated lesion, what might be the trigger?
Amalgam
If there was a lichen planus lesion due to an amalgam restoration , what do we call it ?
Lichenoid reaction to amalgam
3 main contributing factors to oral lichen planus ?
- Idiopathic
- Medication
- Amalgam
Other than beta-adrenergic blockers and ace inhibitors, give 3 groups of drugs that might cause a lichenoid reaction?
- Diuretics - fruseamide
- NSAIDs
- DMARDs
What 3 DMARDs that might cause lichenoid reaction?
- penicillamine
- Gold
- Sulphasalazine
Give 3 characteristics of lichenoid drug reactions?
- more widespread lesions
- often bilateral and mirrored
- poorly responsive to standard steroid treatment
When would you discuss changing medications if it is causing lichenoid reaction?
If it causes the patient severe symptoms
A patient takes ACE inhibitors and it is causing a lichenoid reaction, to which drug would you change this?
AT2 blocker
What would you do to an amalgam restoration if it is causing lichen planus?
Change the restoration, avoid during pregnancy
What 2 special investigation would you want to take for a patient presenting with oral lichen planus ?
- Biopsy
- Blood tests : FBC and haematinics
