Scaly dermatitis affecting the soles of the feet of a person suffering from pellagra, a nutritional deficiency of nicotinic acid, one of the B group vitamins. Pellegra results from a dietary deficiency of either nicotinic acid or the amino acid tryptophan, from which nicotinic acid is synthesized in the body. In addition to the white, scaly patches of dermatitis seen here, other symptoms include diarrhoea and depression.