Princeton's WordNet

1. pellagra, Alpine scurvy, mal de la rosa, mal rosso, maidism, mayidism, Saint Ignatius' itch(noun)

   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