Unilateral linear lichen planus with mucous membrane involvement

Linear lichen planus is a rare distinctive variant of lichen planus (LP) ch aracterized by a pruritic eruption of lichenoid, violaceous papules in a li near distribution that sometimes assume a Blaschko line pattern. We describ e a 33-year-old woman who presented with a 4-month history of a slightly pr uritic unilateral linear array of papular lesions on the left side of her n eck that were clinically and histologically consistent with linear LP. Two months after the onset of her skin disease she developed typical lesions wi th a lacy white pattern on the left lateral aspect of her tongue and the le ft buccal mucosa with a striking predominance for the left side. Clinically the lesions on the patient's neck were similar to lichen striatus or liche noid epidermal naevus, a variant of linear verrucous epidermal naevus. Howe ver, the histological features and the fact that later in the course of her disease the patient developed typical LP of the oral mucosa suggest that t his patient has the rare condition of linear LP with unilateral restriction .