Pellagra is a constellation of signs and symptoms arising secondary to niacin / vitamin B3 deficiency. The symptoms of pellagra include: - Diarrhea - Dementia - Inflammation of skin - Mouth sores There are 2 types of pellagra: - Primary pellagra secondary to dietary deficiency of vitamin B3 - Secondary pellagra due to inability to utilize vitamin B3 Treatment of pellagra is supplementation with niacin. Reference: https://en.wikipedia.org/wiki/Pellagra