A 18-month-old boy from an urban slum in Delhi is admitted with a 4-month history of progressive weight loss, chronic diarrhea, and recurrent respiratory tract infections. On examination, he weighs 7.5 kg (expected 11–12 kg), with severe loss of subcutaneous fat and muscle wasting. His ribs are prominently visible, and his skin hangs loosely over his body. There is no edema. Serum albumin is 2.8 g/dL, and total serum protein is 5.2 g/dL. His mother reports inadequate feeding due to poverty and poor sanitation. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Marasmus ### Key Clinical Features Present **Key Point:** Marasmus is a form of protein-energy malnutrition (PEM) characterized by **severe deficiency of both protein and calories**, resulting in wasting of muscle and fat with **absence of edema**. This child exhibits the classic presentation: 1. **Severe weight loss** — 62.5% of expected weight (7.5/12 kg) 2. **Loss of subcutaneous fat and muscle** — "skin hangs loosely," ribs prominently visible 3. **Absence of edema** — the key distinguishing feature 4. **Chronic malnutrition history** — 4-month progressive course with inadequate feeding ### Biochemical and Clinical Comparison | Feature | Marasmus | Kwashiorkor | Marasmic-Kwashiorkor | |---------|----------|-------------|----------------------| | **Weight Loss** | Severe (often <60% expected) | Moderate (60–80%), masked by edema | Severe | | **Subcutaneous Fat** | Markedly depleted | Relatively preserved | Depleted | | **Muscle Wasting** | Severe | Mild to moderate | Severe | | **Edema** | **Absent** | **Present (bilateral)** | **Present** | | **Serum Albumin** | Low-normal to mildly ↓ (2.5–3.5 g/dL) | Severely ↓ (<2.5 g/dL) | Severely ↓ | | **Hair Changes** | Relatively preserved | Sparse, thin, depigmented | Sparse | | **Skin Changes** | Wrinkled, loose ("old man" appearance) | Dermatitis, flaky paint | Both | | **Hepatomegaly** | Absent or mild | Often present | Often present | | **Immune Status** | Relatively better preserved | Severely impaired | Severely impaired | ### Pathophysiology of Marasmus **High-Yield:** Marasmus results from **chronic, severe caloric restriction** (inadequate food intake due to poverty, poor feeding practices, or malabsorption). The body adapts by: 1. **Catabolizing muscle and fat** for energy (gluconeogenesis) 2. **Maintaining serum albumin** relatively better (due to adaptive protein sparing) 3. **Preserving immune function** better than in kwashiorkor 4. **Preventing edema** because the body conserves sodium and water ### Clinical Pearl **Clinical Pearl:** The **absence of edema in the presence of severe wasting** is the hallmark of marasmus. The child appears "like a little old man" with loose, wrinkled skin. Serum albumin is low but not as severely reduced as in kwashiorkor. ### Diagnostic Criteria (WHO) - Weight-for-height: <60% of expected (or BMI <5th percentile for age) - **No edema** - Severe loss of subcutaneous fat and muscle - Serum albumin: 2.5–3.5 g/dL (may be normal in early stages) - Total serum protein: mildly reduced or normal ## Why This Child Has Marasmus The 4-month history of progressive weight loss with severe wasting, loose skin, and **absence of edema** in the context of chronic inadequate caloric intake (poverty, poor feeding) is diagnostic of marasmus. The serum albumin of 2.8 g/dL is lower than typical for pure marasmus but reflects the severity of malnutrition; it is not as severely reduced as in kwashiorkor.