pellagra n.

chronic disease caused by dietary deficiency (formerly blamed on diseased grain) and characterized by dry, red skin, 1811, from Italian (1770s); according to Watkins, a hybrid formed from Latin pellis "skin" (from PIE root *pel- (3) "skin, hide") + Greek agra "a catching, seizure," related to agrein "to take, seize." But OED suggests it might be originally Italian pelle agra "rough skin." Related: Pellagrous.