A 59-year-old woman sustains second- and third-degree burns to the head and neck, anterior surfaces of both arms, one leg, and the trunk including the genital area. Using the Rule of Nines, which estimate best reflects the total burn area?

• A. 36%
• B. 45%
• C. 46%
• D. 55%

Answer: (D)

Estimating burn size uses the Rule of Nines, which assigns fixed percentages to body regions to quickly approximate total body surface area burned. In adults, head and neck is 9%, each upper limb is 9%, the anterior trunk is 18%, the posterior trunk is 18%, each lower limb is 18%, and the genital area is 1%.

Here, the head and neck burn is 9%. The anterior surfaces of both arms together roughly total 9%. A burn on one leg is 18%. The trunk’s anterior region is 18%, and the genital area (counted separately) adds 1%, giving 19% for that region.

Total: 9 + 9 + 18 + 19 = 55%. This matches the estimated total burn area.