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What is Casal's necklace' is seen in the following disease and explain in detail?
The Casal necklace is an erythematous pigmented skin rash in the distribution of a broad collar (dermatomes C3 and C4). It is seen in patients with pellagra. It occurs as a result of niacin (vitamin B-3) deficiency. Pellagra is a disease characterised by diarrhoea, dermatitis and dementia. Ref : Biochemistry by U. Satyanarayana 3rd edition Pgno : 138-141