noun Pathology. a disease caused by a deficiency of niacin in the diet, characterized by skin changes, severe nerve dysfunction, mental symptoms, and diarrhea.

What does pellagra mean?

Pellagra is a disease caused by low levels of niacin, also known as vitamin B-3. It's marked by dementia, diarrhea, and dermatitis, also known as “the three Ds”. If left untreated, pellagra can be fatal.

Does pellagra still exist?

Pellagra often is considered to be extinct in developed countries, but it still occurs in rare instances. It is caused by niacin deficiency, but can also develop secondary to deficiency of tryptophan, a precursor of niacin.