A 5-year-old girl from a slum in Delhi is admitted with severe malnutrition. Anthropometric measurements show weight-for-age 50% of expected, height-for-age 85% of expected, and weight-for-height 60% of expected. Which finding would best distinguish acute protein-energy malnutrition (PEM) from chronic PEM in this child?

## Acute vs. Chronic Protein-Energy Malnutrition: Anthropometric Discrimination ### Anthropometric Patterns and Timing **Key Point:** The pattern of anthropometric loss distinguishes acute PEM (wasting) from chronic PEM (stunting). Acute PEM causes rapid weight loss while height is preserved; chronic PEM causes loss of both weight and height. | Parameter | Acute PEM (Wasting) | Chronic PEM (Stunting) | |-----------|-------------------|----------------------| | **Weight-for-age** | Markedly reduced (<70%) | Reduced (70–80%) | | **Height-for-age** | Normal or near-normal (>90%) | Markedly reduced (<85%) | | **Weight-for-height** | Severely reduced (<70%) | Near-normal or mildly reduced | | **Onset** | Rapid (weeks to months) | Insidious (months to years) | | **Reversibility** | Highly reversible with nutrition | Partially reversible; permanent stunting | | **Body proportions** | Thin but proportionate | Short but proportionate | | **Muscle mass** | Severely depleted | Relatively preserved | | **Subcutaneous fat** | Severely depleted | Relatively preserved | ### Clinical Interpretation of This Case - **Weight-for-age 50%** → severe underweight - **Height-for-age 85%** → mild-to-moderate stunting (not severely reduced) - **Weight-for-height 60%** → severe wasting (acute component) **Interpretation:** This child has **acute malnutrition superimposed on chronic malnutrition** (mixed form). The preserved height relative to weight loss indicates the acute component is the dominant discriminator. ### High-Yield **High-Yield:** **Wasting = acute PEM** (normal height, low weight). **Stunting = chronic PEM** (low height, low weight). A child with **normal height but severe weight loss** has acute PEM. This distinction is critical for prognosis and intervention timing. ### Mnemonic **WASTING** = **W**eight loss (acute), **A**cute onset, **S**evere (weight-for-height <70%), **T**hin (body proportionate), **I**nterventions (rapid response), **N**ormal height, **G**ood prognosis **STUNTING** = **S**hort stature, **T**ime (chronic, months–years), **U**nderweight (both height and weight), **N**ormal proportions, **T**ime-dependent (irreversible after 2–3 years), **I**nsidious onset, **N**utrition (late intervention less effective), **G**rowth deficit ### Pathophysiology 1. **Acute PEM (wasting):** Recent caloric deficit → rapid mobilization of fat and muscle → weight loss while skeletal growth (height) is temporarily spared 2. **Chronic PEM (stunting):** Prolonged caloric deficit → impaired growth hormone and IGF-1 secretion → reduced linear growth → permanent height loss ### Clinical Pearl **Clinical Pearl:** A child with **normal height and severe weight loss** is acutely malnourished and has excellent prognosis with nutritional rehabilitation. A child with **short stature** has suffered chronic malnutrition and may have permanent growth deficit even after nutritional recovery.