Which condition is primarily characterized by edema due to protein deficiency?

• A. Marasmus
• B. Scurvy
• C. Rickets
• D. Kwashiorkor

Answer: (D)

Edema from protein deficiency occurs because plasma albumin falls when protein intake is severely limited, lowering oncotic pressure that normally keeps fluid inside blood vessels. This leads to fluid leaking into interstitial spaces, which is the hallmark of Kwashiorkor. It typically happens in children who receive enough calories but not enough protein, often after weaning, and is often accompanied by a swollen abdomen, irritability, fatty liver, and skin or hair changes. In contrast, marasmus is driven by overall energy deficiency and shows extreme wasting with little or no edema, while scurvy and rickets result from deficiencies of vitamin C and vitamin D, respectively, and present with different signs such as gum bleeding or bone deformities rather than edema from protein shortage.