Burn classification helps medical science students describe how deeply tissue is injured and how much of the body is affected. This cheat sheet is useful because burn severity guides first aid, triage, transport decisions, and fluid needs. Students need a clear way to compare superficial, partial-thickness, and full-thickness burns.
The Rule of Nines gives a fast estimate of total body surface area burned in adults.
Key Facts
- Superficial burns involve only the epidermis and usually cause redness, pain, and no blisters.
- Partial-thickness burns involve the epidermis and part of the dermis and often cause blisters, swelling, and significant pain.
- Full-thickness burns destroy the epidermis and dermis and may look white, brown, black, leathery, or painless because nerves are damaged.
- Total body surface area burned, or TBSA, estimates the percent of the body with partial-thickness or full-thickness burns.
- In the adult Rule of Nines, the head and neck equal 9%, each arm equals 9%, each leg equals 18%, the front trunk equals 18%, the back trunk equals 18%, and the perineum equals 1%.
- Do not count superficial first-degree burns in TBSA calculations for fluid resuscitation decisions.
- The palm method estimates burn size by using the patient’s palm and fingers as about 1% of TBSA.
- A common initial fluid estimate is the Parkland formula: fluid in first 24 hours = 4 mL x body mass in kg x percent TBSA burned.
Vocabulary
- Burn
- A tissue injury caused by heat, chemicals, electricity, radiation, or friction.
- Epidermis
- The outermost layer of skin that helps protect the body from infection and water loss.
- Dermis
- The deeper skin layer containing blood vessels, nerves, sweat glands, and hair follicles.
- Partial-thickness burn
- A burn that damages the epidermis and part of the dermis, often producing blisters and severe pain.
- Full-thickness burn
- A burn that destroys the epidermis and dermis and may damage deeper tissues.
- TBSA
- Total body surface area, the percentage of the body affected by partial-thickness and full-thickness burns.
Common Mistakes to Avoid
- Counting red, unblistered superficial burns in TBSA is wrong because TBSA estimates for burn resuscitation include partial-thickness and full-thickness burns.
- Using the adult Rule of Nines for young children is wrong because children have proportionally larger heads and smaller legs than adults.
- Adding both sides of a limb incorrectly is wrong because the Rule of Nines values usually include the entire limb unless a front or back portion is specified.
- Assuming painless burns are minor is wrong because full-thickness burns can destroy nerve endings and reduce pain sensation.
- Ignoring airway risk in face, neck, or smoke inhalation burns is wrong because swelling can block breathing even if the skin burn looks limited.
Practice Questions
- 1 An adult has partial-thickness burns on the entire right arm and the entire front trunk. What percent TBSA is burned using the Rule of Nines?
- 2 An adult has full-thickness burns on the entire left leg and superficial redness on the right forearm. What percent TBSA should be counted for burn severity?
- 3 Using the Parkland formula, estimate the first 24-hour fluid amount for a 70 kg adult with 30% TBSA burns.
- 4 A patient has a white, leathery burn on the hand and says it does not hurt much. Explain why this can still be a severe burn.