Case Presentation: A 53-year-old man presented with diarrhea and an unintentional 30 lb weight loss over four months. He had also been experiencing intermittent abdominal pain for which he adopted a diet limited to soft foods and liquids. His past medical history was significant for a recently diagnosed deep vein thrombosis, Crohn’s disease, depression, hypothyroidism, and exfoliative dermatitis. He was adherent to his medications:  levothyroxine, low-dose prednisone, folic acid, and adalimumab. He was bradycardic to 43 bpm and his body mass index measured 17.7 kg/m­­2. He was extremely apathetic when discussing his issues and severely cachectic. His skin had a diffuse, scaly, exfoliative dermatitis involving sun-exposed areas, as well as scattered hyperpigmentation of the upper and lower extremities. There were no extraintestinal manifestations of Crohn’s disease noted. Complete metabolic panel revealed hypoalbuminemia (2.3 g/dL) and low total protein (4.8 g/dL). EGD showed mucosal atrophy of the stomach and first portion of the duodenum. Colonoscopy demonstrated evidence of scattered colonic fibrosis and a stricture near the terminal ileum. No endoscopic or histologic signs of active Crohn’s disease were noted. Nutritional evaluation revealed borderline low vitamin A (37 mcg/dL), and undetectable levels of niacin and nicotinamide (<20ng/mL). Vitamin D 25-OH, vitamin E, folic acid, and vitamin B12 were all within normal limits. The patient was diagnosed with pellagra and was started on total parental nutrition, oral niacin, and topical hydrophilic cream. After three days of total parental nutrition and nutritional supplementation, the patient’s pulse increased to approximately 65 bpm.

Discussion: The characteristic “D’s” of Niacin deficiency, known as Pellagra, are common complaints that a Hospitalist sees everyday. These refer to dermatitis, diarrhea, dementia, and occasionally death. Niacin deficiency is most prevalent in populations with predominantly maize-based diets. For this reason, pellagra is not commonly considered in the differential diagnosis when patients present with its classic symptoms but consume a typical American diet. Untreated pellagra can lead to increased morbidity and mortality but can be easily corrected with supplemental niacin if the deficiency is detected. The signs and symptoms can be subtle and are frequently attributed to other medical conditions so niacin levels are not routinely checked. Due to the possibility of niacin deficiency in patients with malabsorption, the Hospitalist must consider pellagra in the differential diagnosis and workup of a patient with dermatitis, diarrhea, dementia and/or other subtle neuropsychiatric disturbances, regardless of diet.

Conclusions: The Hospitalist must be able to recognize niacin deficiency and understand common predisposing conditions in order to prevent this easily treated but potentially lethal condition.