Background
- Lichen Planus is a chronic mucocutaneous dermatosis of unknown aetiology
- Usually in patients >45; incidence ~27/100,000
- Can be precipitated by trauma (Koebner’s phenomenon) (areas of trauma affected); viral infection and there is likely to be a genetic component (tends to occur in families)
- Associated with Primary Biliary Sclerosis
- A lichenoid skin eruption may also be caused by drugs e.g. Gold, hydroxychloroquine and captopril
Presentation
- In the mouth- can cause chronic areas of white striae, plaques and erosions which may be painful (particularly with irritant foods e.g. spicy)
- In the skin, violaceous polygonal papules; intensely itchy; classically over the flexor surfaces of the wrist, forearms and shins
- Nail involvement may cause pitting, ridging and nail loss
- Scalp involvement may cause alopecia
Types of Lichen Planus (many others)
- Hypertrophic – thickened lesions which typically affect the shins/ankles (can cause scarring)
- Annular – ring-shaped- typically affecting the armpits/creases
- Pigmentosa – causes pigmentation of the skin (more common in dark skinned individuals)
- Actinic – sun-exposed areas
Management
- Topical corticosteroid if required
Notes on Medicine/Surgery 