[Skin Manifestations of Pellagra].

Pellagra is a type of dietary deficiency disease caused by an insufficiency of niacin or tryptophan. Symptoms of pellagra include diarrhea, dermatitis, and dementia. It is usually diagnosed based on a patient's dietary history and clinical symptoms. The diagnostic triad of pellagra includes symptoms of dermatitis, dementia, and diarrhea. Dermatitis is important for the diagnosis of this condition, because dementia and diarrhea show low specificity. In the modern era, pellagra rarely occurs in developed countries. However, pellagra should be considered in the differential diagnoses of dermatitis occurring on the sun-exposed areas of skin. Additionally, a hypoalimentation state with concomitant vitamin and/or zinc deficiency is observed in patients with pellagra. After checking the patient's overall nutritional status specifically with respect to pellagra, it is important to provide adequate food, supplemented with vitamins, zinc, and nicotinic acid to treat the patient's nutritional deficiencies.