<prompt> What is the name of this appearance which is seen in pellagra?BurnCasals necklaceShawl signGottrons papule  <response>: This is Casals necklace shown in picture, which occurs in Vitamin B3 Niacin deficiency. Niacin is formed from tryptophan amino acid. So, tryptophan deficiency can lead to Casals necklace. Pellagra Etiology: Dietary deficiency of Niacin or its precursor tryptophan. Cf: Middle aged persons Pellagra: - Dermatitis, Dementia, Diarrhea, Death Tt: Niacinamide 300-500mgdayorally in divided doses. 