Chronic Diarrhea and Alcoholism: Unravelling the Connection to Pellagra.

Pellagra is a deadly systemic disease caused by niacin deficiency or a disorder of its metabolism. It typically presents as a classic triad of diarrhea, dermatitis, and dementia. It is increasingly seen among high-risk populations such as those with poor socioeconomic status, immunocompromised states, chronic alcoholism, malabsorption disorders, and populations heavily reliant on a corn-based diet. We report a case of a 39-year-old man presenting with watery diarrhea and hyperpigmentation over the sun-exposed areas of the face and arms, with a history of alcohol use disorder. Differential diagnoses were excluded. Niacinamide supplements and lifestyle modifications were recommended, resulting in the resolution of the symptoms. This case report emphasizes the need for a high index of suspicion when diagnosing pellagra in vulnerable populations to ensure prompt treatment and recovery.