a disease caused by deficiency of niacin or tryptophan (or by a defect in the metabolic conversion of tryptophan to niacin); characterized by gastrointestinal disturbances and erythema and nervous or mental disorders; may be caused by malnutrition or alcoholism or other nutritional impairments同义词：pellagra, Alpine scurvy, mal rosso, maidism, mayidism, Saint Ignatius' itch
