A 2-year-old child presents with bilateral pitting oedema, skin lesions ('flaky paint' dermatosis), pale sparse hair, and a 'miserable' affect. Weight-for-height Z-score is −1.5. The MOST likely diagnosis and its primary biochemical defect are:

• A Marasmus — severe energy deficiency with intact albumin synthesis
• B Marasmic-kwashiorkor — combined severe protein and energy deficiency
• C Kwashiorkor — protein deficiency causing hypoalbuminaemia and oedema ✓
• D Vitamin A deficiency — defective immune function causing secondary oedema

Explanation

The clinical triad of bilateral pitting oedema, dermatosis ('flaky paint' or 'crazy pavement' pattern), and depigmented/sparse hair with preserved weight-for-height characterises Kwashiorkor. The primary biochemical defect is protein deficiency leading to hypoalbuminaemia (< 3 g/dL) and reduced oncotic pressure causing oedema. In marasmus, the child appears wasted with visible ribs/wrinkled skin but no oedema. Marasmic-kwashiorkor combines wasting WITH oedema.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.