Alcoholic Pellagra as a Cause of Altered Mental Status in the Emergency Department

Pellagra, which is caused by a deficiency of niacin and tryptophan, the precursor of niacin, is a rare disease in developed countries where alcoholism is a major risk factor due to malnutrition and lack of B vitamins. Although pellagra involves treatable dementia and psychosis, it is often underdiagnosed, especially in developed countries.

In Japan, a 37-year-old man presented to the emergency department with altered mental status and seizures. Wernicke encephalopathy and alcohol withdrawal were suspected. The patient was treated with multivitamins, which did not include nicotinic acid amide, and oral diazepam. Despite medical treatment, his cognitive impairment progressively worsened, and eventually, pellagra was suspected. His response to treatment with nicotinic acid amide was substantial, and he was discharged without any long-term sequelae. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Despite the treatable dementia and psychosis, pellagra is often underdiagnosed, especially in developed countries and alcoholic patients. Pellagra should be routinely suspected in alcoholic patients because the response to appropriate treatment is typically dramatic.