Overview
Definition
A chronic inflammatory skin and mucosal disease characterized by itchy, polygonal, flat-topped violaceous papules.
Epidemiology
Affects <1% of the population. Association with active Hepatitis C virus (HCV) infection.
Etiology & Risk Factors
- T-cell mediated autoimmune reaction targeting basal keratinocytes
Clinical Symptoms
- The '6 Ps': Pruritic, Polygonal, Purple/Violaceous, Planar (flat-topped), Papules, and Plaques
- Wickham's striae (fine white lacy lines on papules or oral mucosa)
- Distribution: Flexor wrists, ankles, lumbar region
- Oral Lichen Planus: Lacy white lesions or painful erosions in mouth
- Nail thinning, ridging, and pterygium formation
Clinical Approach
Diagnosis
- Clinical presentation
- Skin biopsy showing band-like lymphocytic infiltrate at the dermal-epidermal junction and saw-tooth rete ridges
- Hepatitis C screening
Management
- High-potency topical corticosteroids (Clobetasol)
- Intralesional steroid injections for thick plaques
- Systemic steroids or retinoids for severe, generalized disease
- Oral hygiene for mucosal LP
Complications
- Oral squamous cell carcinoma (in chronic erosive oral LP, requires surveillance)
- Post-inflammatory hyperpigmentation