In wof Wickham&;s striae are seen

Lichen Planus * Pruritic papular disease of skin and mucous membranes * Due to cell-mediated autoimmune reaction toward basal layer keratino-cytes; may be idiopathic, drug-related or infection-related (HCV) * 4P's: papular, pruritic, polygonal, purple * Often lasts 1-2 years (except oral and hyperophic forms, which typically have protracted courses) * Presents with intense pruritus and violaceous, smooth flat-topped papules and plaques with fine scale (Wickham's striae) over flexor wrists, forearms, legs, presacrum and other areas, + Koebner phenomenon * No conclusive evidence to suppo association with autoimmune disease (per Bolognia); difficult to determine if true HLA association Histology:- * Hyperkeratosis (without parakeratosis) * | Granular layer * Paially effaced rete ridges with widened papillae ('sawtooth' appearance) * Vacuolar change of basal layer with colloid bodies * Band-like lymphocytic infiltrate at dermoepidemal junction * Dermal melanophages Treatment:- superpotent topical coicosteroids, topical calcineurin inhibi tors, intralesional or systemic coicosteroid, phototherapy, methotrexate, acitretin, metronidazole (latter for erosive oral form). Ref:- Sima Jain; pg num:- 106,108