Snapshot A 49-year-old woman with chronic hepatitis C infection develops a very itchy rash on her forearms, calves, and buccal mucosa. On exam, multiple polygonal, purple papules are found on the skin. The buccal mucosa shows a lacy, reticulated pattern. She has taken antihistamines with some relief of pruritis. Introduction An uncommon, pruritic, inflammatory lesion most commonly involving wrists, ankles, mucosa 6 P’s pruritic planar polygonal purple papules plaques Epidemiology affects women > men Associated conditions HCV, especially with mucosal involvement of lichen planus Presentation Symptoms insatiable itch Physical exam skin purple papule with angulated (polygonal) border can have vesicles or bullae can result in scarring alopecia mucosa white, lacy, reticulated patches in oral mucosa = diagnostic of lichen planus known as Wickham striae nail dystrophic Evaluation Skin biopsy sawtooth infiltrate of lymphocytes at dermal-epidermal junction Differential Psoriasis Papular eczema Discoid lupus (if scarring alopecia) Treatment Medical treatment antihistamines for pruritus topical steroids for localized disease Prognosis, Prevention, and Complications Prognosis course is variable and unpredictable Complications < 5% of cases of oral lesions progress to squamous cell carcinoma