burn area extent

Last reviewed 10/2022

Along with depth of burn and burning agent, another key determinant of seriousness is the area of skin damaged. It is essential to estimate the area burnt to guide fluid resuscitation.

The recommended technique is by the Rule of Nines - see submenu.

For children and for small burns, an alternative method is to estimate the extent of the burn by comparison with the area of the patient's hand. The area of the fingers and palm roughly equates to a 1% total body surface area burn. One way of engaging the distressed child in the task of estimating the burn area is to draw around the fingers and palm. Then this paper template is cut out and placed against the burn to estimate its area.

For large burns, subtract the unburnt area from 100. Also, as a way of checking an estimate of burn area whatever technique is applied, it is prudent to calculate both the burnt and unburnt areas to see if the figures correspond.

The total body surface area burnt directly relates to the ultimate mortality from the injury.