Linear lichen planus

Linear lichen planus is a rare clinical variant of lichen planus (LP) in which the characteristic lesions arrange themselves in a linear or band-like distribution along the skin. Lichen planus is a chronic inflammatory condition that primarily affects the skin and mucous membranes, and in the linear form, violaceous (purple-hued), flat-topped, polygonal papules and plaques follow the lines of Blaschko or, less commonly, a dermatomal pattern. The lesions are typically pruritic (itchy) and may appear on the extremities, trunk, or face. The condition can affect individuals of any age but is more commonly reported in adults. Linear lichen planus may sometimes be confused with other linear dermatoses such as linear psoriasis, lichen striatus, or inflammatory linear verrucous epidermal nevus (ILVEN). The exact cause of linear lichen planus remains unclear, though it is believed to involve a T-cell-mediated autoimmune response directed against basal keratinocytes, similar to classic lichen planus. The linear distribution along Blaschko lines suggests a possible role of genetic mosaicism in predisposing certain skin cell populations to the inflammatory process. Histopathologically, the condition shows the hallmark features of lichen planus, including a band-like lymphocytic infiltrate at the dermoepidermal junction, irregular acanthosis, wedge-shaped hypergranulosis, and civatte bodies (apoptotic keratinocytes). Treatment of linear lichen planus follows the general approach used for lichen planus. First-line therapy typically includes potent topical corticosteroids to reduce inflammation and pruritus. Topical calcineurin inhibitors (such as tacrolimus) may also be used, particularly for sensitive areas. For more extensive or refractory cases, phototherapy (narrowband UVB), systemic corticosteroids, oral retinoids (acitretin), or other immunomodulatory agents may be considered. The condition is generally self-limiting, with most cases resolving over months to years, though post-inflammatory hyperpigmentation may persist. Regular follow-up is recommended to monitor for recurrence and to manage symptoms.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Linear lichen planus