Pellagra
/pəˈlæɡrə/noun
A disease caused by niacin deficiency, marked by dermatitis, diarrhea, and dementia.
Did you know?The word comes from Italian, where *pelle* means “skin” and *agra* means “sour” or “rough,” so the disease was named for the skin damage it caused before doctors knew the vitamin deficiency behind it.
Etymological Timeline
Italian dialect
Italian
pellagra
“rough skin; the disease marked by rough, inflamed skin”
18th Century
Italian
pelle agra
“literally “rough skin””
Early Modern Latin
Latin
pelle + aeger/acer?
“later scholarly attempts to explain the term, but the standard origin is Italian dialectal”
20th Century
English
pellagra
“a deficiency disease caused by lack of niacin”