Lichen Planus

Lichen planus (LP) manifests as pruritic, violaceous polygonal papules and plaques, primarily on flexor wrists, lower legs, and oral mucosa. The condition involves T-cell mediated attack on skin basal cells, leading to vacuolar degeneration without a clear cause, though hepatitis C links exist. Lesions feature Wickham striae, visible as fine white reticular lines, best seen dermoscopically.?

Types and Sites

Cutaneous LP affects skin symmetrically; oral form shows white lacy patches or erosions inside cheeks; genital variants cause painful erosions. Nail involvement leads to ridging or pterygium; lichen planopilaris scars scalp hair follicles. Rare esophageal or laryngeal LP risks strictures or malignancy.?

Diagnosis and Management

Diagnosis relies on clinical 6 Ps (purple, polygonal, planar, pruritic, papules, plaques) or biopsy showing lichenoid infiltrate. Topical corticosteroids like clobetasol are first-line; severe cases use oral retinoids or immunosuppressants. Most cutaneous cases resolve in 1-2 years, but mucosal forms persist.