A 3-year-old boy from rural Maharashtra is brought to the primary health centre with a 6-month history of poor weight gain, recurrent infections, and diarrhoea. On examination, he weighs 10 kg (expected 14 kg for age), height 85 cm, appears alert and interactive, with mild bilateral pitting oedema over the shins. Serum albumin is 2.8 g/dL (normal 3.5–5.0), total protein 5.2 g/dL, and haemoglobin 9.2 g/dL. What is the most likely diagnosis?

## Clinical Diagnosis: Kwashiorkor ### Key Clinical Features Present **Key Point:** Kwashiorkor is protein deficiency with relatively preserved caloric intake, characterized by oedema, hepatomegaly, and biochemical hypoalbuminaemia despite weight loss. This child presents with the classic triad: 1. **Bilateral pitting oedema** — pathognomonic for kwashiorkor (due to low plasma oncotic pressure from hypoalbuminaemia) 2. **Preserved alertness and interaction** — distinguishes from marasmus (child appears apathetic) 3. **Hypoalbuminaemia (2.8 g/dL)** — indicates severe protein deficiency ### Differential Diagnosis: PEM Subtypes | Feature | Kwashiorkor | Marasmus | Marasmic-Kwashiorkor | |---------|-------------|---------|----------------------| | **Onset** | Acute (weeks–months) | Chronic (months–years) | Mixed, acute on chronic | | **Oedema** | Present, bilateral | Absent | May be present | | **Albumin** | <2.5 g/dL (low) | Often normal/near-normal | Low | | **Appearance** | "Moon face", pot belly | Wasted, wizened | Wasted + oedema | | **Alertness** | Apathetic, withdrawn | Alert, irritable | Variable | | **Hair changes** | Sparse, depigmented | Sparse | Sparse | | **Skin lesions** | Dermatitis (peeling) | Minimal | Present | ### Biochemical Rationale **High-Yield:** Serum albumin <2.8 g/dL with oedema is diagnostic of kwashiorkor. Albumin has a half-life of 20 days and reflects recent protein intake; low levels indicate acute protein deficiency despite possible adequate carbohydrate/fat intake. **Clinical Pearl:** The presence of oedema in a malnourished child is the single most reliable clinical discriminator — it indicates kwashiorkor, not marasmus. Marasmic children are "skin and bones" with no fluid retention. ### Pathophysiology 1. Inadequate dietary protein (common in cereal-based diets in India) 2. Reduced hepatic albumin synthesis 3. Loss of plasma oncotic pressure → transcapillary fluid shift → oedema 4. Impaired immune function → recurrent infections 5. Fatty infiltration of liver (hepatomegaly may develop) **Mnemonic:** **KWASH** = **K**washi (Akan word for "disease of the deposed child") — occurs when a child is weaned onto carbohydrate-rich but protein-poor foods (e.g., cassava, rice without legumes). ## Management Approach Initial management includes: - Gradual refeeding (avoid refeeding syndrome) - Micronutrient supplementation (zinc, iron, vitamins A, B, C) - Treatment of infections - Monitoring for hypoglycaemia and electrolyte disturbances **Warning:** Do NOT overfeed acutely — risk of cardiac failure, pulmonary oedema, and refeeding syndrome due to shifts in K^+^, Mg^2+^, and phosphate.