An 86-year-old woman affected by mild cognitive impairment presented to our institution with complaints of intense headache, vomiting and fever since 2days, complicating a 4-month history of mucosal ulcerations and progressive papulopustular skin lesions of the whole body. She had been diagnosed with scleroatrophic lichen, and a biopsy of the tongue had shown epithelial ulceration and an intense perivascular inflammatory infiltrate of the lamina propria rich in plasma cells. On examination, the patient was febrile but alert; no neck stiffness or change in mental status were present.