A Case of Linear Hypertrophic Lichen Planus in a Pediatric Patient.

Lichen planus (LP) is a chronic inflammatory disease of the skin and mucosa. Of the various types, the hypertrophic type is characterized by thickened, purplish hyperkeratotic plaques and nodules. The course of hypertrophic LP tends to be more chronic than those of other types. A 12-year-old girl presented with a 2-year history of warty papules and plaques in a zosteriform configuration along one flank. Histopathology revealed hyperkeratosis and papillomatosis with wedge-shaped hypergranulosis. A lichenoid lymphocytic infiltrate with vacuolar change in the basal layer was evident. She was prescribed oral doxycycline, a topical corticosteroid, and tacrolimus. After 7 weeks, the skin lesions became significantly flattened and faded. LP is less common but more severe in children than in adults. The unilateral, linear hypertrophic type of LP is uncommon. Herein, we report a rare case of linear hypertrophic LP in a child.