Pellagra: An Unusual Cause for Altered Mental Status.

Pellagra, a rare disorder caused by niacin deficiency, manifests as 4Ds: dermatitis, diarrhea, dementia, and, if left untreated, death. Though it was thought to be eradicated from the United States after fortification with niacin, there have been concerns about its reemergence in specific high-risk populations such as chronic alcoholism, malabsorption, and anorexia nervosa. Here we present a patient with altered mental status who subsequently developed diarrhea during the course of hospitalization. After extensive workup, the final diagnosis was determined to be pellagra. The patient was administered niacin, resulting in subsequent improvement, and was discharged in stable condition from the hospital. Our case report highlights the importance of considering pellagra in the differential diagnosis for certain high-risk patients presenting with altered mental status as it has not been completely eradicated yet.