Depth and Extent of Burns. Guidelines

depth-and-extent Depth and Extent of Burn

Depth or Thickness

What does burn thickness mean? and what difference does it make?

Burn thickness is important because the different layers of the skin all have many different functions. Your skin protects and insulates you. It can grow new skin, regulate body temperature, grow hair, guard against infection and communicate with your brain about what your environment feels like. The supple flexibility of your skin allows you to move and breath.

How deep a burn penetrates through the layers of the skin determines which of these functions may be damaged and which of these functions may be lost forever. A close inspection of the texture, moisture, color and general appearance of a burn will give you important clues regarding what thickness or “degree” of burn the patient has suffered.

BUT don't waste time trying to assess the depth .


    Superficial Burn        Partial Thickness Burn   Full Thickness Burn
Depth of Burns

In Calculating the Percentage of Body Surface area that has been affected by burns, the following guide is universally used.
  • For smaller burns, the palm of the patient's hand is 1%, not including the fingers.
  • The head is 9%.
  • The chest and back are both 18% respectively.
  •  Each leg is also 18%.
  • Each arm is given 9%
  • The genitalia add the remaining 1% to total body area.
From that foundation, large area burns can be estimated rapidly, for example
One half of one arm is a 4.5% of TBSA (Total Body Surface Area).
One entire leg and the front of the other leg is a 27% of TBSA burn.
  • The patient should see a physician if,

  • more than 1% of skin surface is involved.

  • Face, neck, genital area, hands, or feet are involved.

  • Any child under 12 suffering from burns or scalds

Prompt cooling of the burn can prevent a second degree burn from escalating to a Full Thickness Burn.
A burn from Gasoline can continue to penetrate tissue for 17 minutes.
So continue to cool the area for at least 20 minutes, but no longer, as it may reduce the blood supply to the injury.

Only ever use COOL water, never Cold Water

Return to Burns and Scalds from Depth and Extent
Return to Burn First Aid from Depth and Extent