Pellagra : Pellagra is a vitamin deficiency disease most frequently caused by a chronic lack of niacin (vitamin B3) in the diet. It can be caused by decreased intake of niacin or tryptophan and possibly by excessive intake of leucine. Pellagra is clinically manifested by the 4 D’s: photosensitive dermatitis, diarrhea, dementia, and death. The full tetrad of symptoms is usually not well developed in infants and children. This vitamin deficiency responds to treatment with nicotinic acid Oral therapy with nicotinamide or niacin usually is effective in reversing the clinical manifestations of pellagra. Because patients are often malnourished and have other vitamin deficiencies, provisions for a high-protein diet and the administration of B-complex vitamins are needed for complete recovery.