pellagra /pəlā″grə, pəlag″rə/ [It, pelle, skin, agra, rough] , a disease resulting from a deficiency of niacin or tryptophan or a metabolic defect that interferes with the conversion of the precursor tryptophan to niacin. It once was commonly seen in individuals whose diet consisted primarily of corn, which is low in tryptophan. Compare kwashiorkor. Kinds include pellagra sine pellagra, typhoid pellagra. −pellagrous, adj. ▪ OBSERVATIONS: It is characterized by scaly dermatitis, especially of the skin exposed to the sun; glossitis; inflammation of the mucous membranes; diarrhea; and mental disturbances, including depression, confusion, disorientation, hallucination, and delirium. ▪ INTERVENTIONS: Treatment and prophylaxis consist of the administration of niacin and tryptophan, usually in conjunction with other vitamins, particularly thiamine and riboflavin, and a well-balanced diet containing foods rich in these nutrients, such as liver, eggs, milk, and meat. ▪ PATIENT CARE CONSIDERATIONS: Patients usually do well following the correction of niacin levels.