In a child aged 5 years with a burn injury, which modification to the Rule of Nines is most appropriate for calculating body surface area?

Explanation

## Rule of Nines Modification in Pediatric Burns **Key Point:** The Rule of Nines must be modified in children because their head is proportionally larger and legs are proportionally smaller compared to adults. ### Pediatric Rule of Nines Modification | Body Region | Adult | Child (5 years) | Infant (< 1 year) | | --- | --- | --- | --- | | Head and neck | 9% | 18% | 21% | | Each arm | 9% | 9% | 9% | | Chest | 9% | 9% | 9% | | Abdomen | 9% | 9% | 9% | | Each leg | 18% | 13.5% | 13.5% | | Genitalia | 1% | 1% | 1% | **High-Yield:** The key pediatric modification is: **Head doubles (18%) and each leg decreases (13.5%)** to account for the child's relatively larger head and shorter legs. **Mnemonic:** **"Bigger Head, Smaller Legs"** - Children have proportionally larger heads (18% vs 9%) - Children have proportionally smaller legs (13.5% vs 18%) - The difference is redistributed: +9% to head, -4.5% per leg **Clinical Pearl:** Using the adult Rule of Nines in a child would significantly underestimate head burns and overestimate leg burns, leading to incorrect fluid resuscitation calculations. This is a critical safety consideration in pediatric burn management. [cite:Reddy and Menon Forensic Medicine 33e Ch 12]