Lichen Planus Quick Review

Overview

• Idiopathic inflammatory disease affecting skin, hair, nails, and mucous membranes

Pathogenesis

• T-cell–mediated autoimmune attack on basal keratinocytes
• Association with HCV: $2-14$-fold increased prevalence

Clinical Features

• Primary lesion: polygonal, violaceous, flat-topped papule
• Surface appears shiny/transparent
• Wickham’s striae (network of fine white lines)
• Intense pruritus
• Koebner phenomenon (lesions at trauma sites)

Common Sites of Involvement

• Flexor wrists & forearms
• Dorsal hands
• Anterior lower legs
• Neck & presacral region
• Oral mucosa, glans penis
• Nails and scalp hairs

Differential Diagnosis

• Lupus erythematosus (LE)
• Pityriasis rosea
• Psoriasis

Treatment Options

• Topical corticosteroids
• Intralesional corticosteroids
• Systemic corticosteroids
• PUVA (psoralen + UVA)
• Cyclosporine
• Antihistamines