This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Medicine
Non pitting edema is seen in ? 
Select and explain. 
A. Congestive cardiac failure, B. Myxedema, C. Liver failure, D. Renal failure
B: Myxedema
Answer: B: Myxedema 
Explanation: A consequence of prolonged hypothyroidism is increased dermal infiltration of glycosaminoglycans (mucopolysaccharides, hyaluronic acid and chondroitin sulphate) which traps water, giving rise to skin thickening without pitting (myxedema). Typical features include a puffy face with edematous eyelids and nonpitting pretibial edema. Reference : page 2291 Harrison's Principles of Internal Medicine 19th edition and page 743 Davidson's Principles and practice of Medicine 22nd edition