May be caused by malnutrition or alcoholism or other nutritional impairments

• 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

WordNet Word definitions in WordNet
n. 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 ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Pellagra \Pel"la*gra\ (p[e^]l"l[.a]*gr[.a]), n. [It. pelle skin + agro rough.] (Med.) An affection of the skin, characterized by redness, especially in exposed areas, scaling and shedding of the skin, and accompanied with severe gastrointestinal disturbance ...