Isolated linear lichen planopilaris: extremely rare when limited to the scalp.

Lichen planopilaris (LPP) is a primary cicatricial alopecia that rarely presents in a linear distribution. We present a case of linear LPP that was isolated to the frontal scalp with extension down the forehead. It is uncommon to see a linear distribution of LPP anywhere on the body, but it is particularly rare on the scalp. We also discuss the pathophysiology of disorders that present in unusual linear distributions.