Generally the classification for the medical treatment purposes it is as follows(including the Burns and Psychiatry):
2-12 childhood; 13-18 adolescence; after 18- adulthood. However hard and fast rule with the strict age limit is not set forth for calculation(in literature I learnt), meaning, there will always be some overlapping, especially in childhood range.
Lund and Browder chart illustrating the method for calculating the percentage of body surface area affected by burns in children.
If the chart is unavailable, estimate BSA by the Rule of Nines and adjust for age as follows:
"In children younger than 1 year, the head and neck are 18% of BSA and each leg is 15% of BSA. The torso and arms represent the same percentages as in adults (10% and 16%, respectively).For each year older than 1 year, add 0.5% to each leg and decrease percentage for the head by 1% until adult values are reached."
Lund and Browder chart
This assessment chart has been developed to assist health professionals to accurately calculate the percentage of burn surface area. It allows for the varying rates of growth in the head, thigh and lower leg of different age groups.
The "Rule of 9's" is considered by some in practice, inaccurate for paediatric patients, however, it is useful as a rough estimate until the Lund & Browder Chart can be used.
This size of the child's palm can be used to estimate 1% Body Surface Area, and
the fluid resuscitation for children: This is given at 15-20% TBSA
But for us what our manual directs is our gold standard for calculation and coding purposes!!