This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Social & Preventive Medicine
Casals Necklace pattern is seen in 
Select and explain. 
A. Thiamine deficiency, B. Riboflavin deficiency, C. Niacin deficiency, D. All of the above
C: Niacin deficiency
Answer: C: Niacin deficiency 
Explanation: (C) Niacin deficiency # Casal collar or Casal Necklace is a clinical sign in which there is an erythematous pigmented skin rash in the distribution of a broad collar (dermatomes C3 and C4). It is seen in patients with pellagra.