Correct Answer: B. 25-30%
Burn surface area calculation in children uses the Rule of Nines, but with age-specific modifications because children have proportionally larger heads and smaller legs compared to adults. In a preschool child (typically 2–5 years), the head and neck account for 18–20% of total body surface area (compared to 9% in adults), while each lower limb accounts for 13–14% (compared to 18% in adults). The anterior and posterior trunk each represent 18%, and each upper limb 9%. When a preschool child presents with burns involving the head, neck, and bilateral upper limbs (as typically shown in such clinical scenarios), the calculation is: head/neck (~18%) + bilateral upper limbs (9% + 9% = 18%) = approximately 25–30% total body surface area. This modified Rule of Nines is the standard approach taught in Indian surgical textbooks and used in burn units across India. Accurate estimation is critical for fluid resuscitation (Parkland formula: 4 mL × %TBSA × body weight in kg), as underestimation leads to inadequate resuscitation and shock, while overestimation causes fluid overload and pulmonary edema. The image-based assessment requires recognition of the child's age-specific body proportions and systematic application of the pediatric Rule of Nines.
Why the other options are wrong
A. 10-15% — This represents underestimation of the burn area. A 10–15% TBSA would correspond to only the head or bilateral upper limbs alone, not their combination. This trap catches students who either miscount body regions or fail to apply the pediatric Rule of Nines correctly. Underestimation is dangerous clinically, as it leads to inadequate fluid resuscitation and hypovolemic shock. C. 15-20% — This represents a partial but incomplete burn assessment. A 15–20% TBSA might correspond to the head/neck plus one upper limb, or the trunk alone. This is a common trap for students who either miss counting bilateral involvement or apply adult Rule of Nines proportions to a child, failing to account for the child's larger head percentage. D. 35-40% — This represents overestimation, suggesting inclusion of additional body regions (e.g., head, bilateral upper limbs, AND part of trunk). This trap appeals to students who are overly cautious or who misapply the adult Rule of Nines (where head = 9% instead of 18% in children). Overestimation causes unnecessary aggressive fluid resuscitation, risking pulmonary edema and complications.
High-Yield Facts
- Pediatric Rule of Nines: Head/neck = 18–20% (vs. 9% in adults); each lower limb = 13–14% (vs. 18% in adults); anterior/posterior trunk = 18% each; each upper limb = 9%.
- Parkland Formula for fluid resuscitation: 4 mL × %TBSA × body weight (kg), with half given in first 8 hours and half over next 16 hours; accurate TBSA estimation is essential.
- Burns >15% TBSA in children require hospital admission and IV fluid resuscitation; <10% can often be managed as outpatient in India.
- Lund and Browder Chart is more accurate than Rule of Nines for precise TBSA calculation, especially in children with irregular burn patterns.
- Age-specific modifications are critical: preschool children (2–5 years) have different proportions than infants (<2 years) or school-age children (>5 years).
Mnemonics
Pediatric Rule of Nines (Modified) HEAD = 18% (not 9%), TRUNK = 36% (18% front + 18% back), ARMS = 18% (9% each), LEGS = 28% (14% each). Use this for children <10 years; adult proportions apply after age 15. TBSA Estimation Trap Don't apply adult Rule of Nines to children. Adult head = 9%; child head = 18%. This single error can halve or double your TBSA estimate. Always check the patient's age first.
NBE Trap
NBE commonly pairs pediatric burn questions with adult Rule of Nines proportions to trap students who memorize without age-stratification. Alternatively, it presents images where bilateral involvement is subtle, tempting students to undercount and select 10–15% instead of the correct 25–30%.
Clinical Pearl
In Indian burn units, a preschool child with 25–30% TBSA burns meets criteria for referral to a tertiary burn center and requires aggressive fluid resuscitation. Underestimation by even 5–10% can result in shock and multi-organ failure; this is why the pediatric Rule of Nines is non-negotiable in pediatric trauma protocols across AIIMS and other Indian teaching hospitals.
_Reference: Bailey & Love Ch. 32 (Burns); Robbins Ch. 9 (Thermal Injury); OP Ghai Ch. 18 (Pediatric Burns)_