Severity Assessment

Part of First Aid

Before you can treat a burn, you must accurately assess how deep it goes and how much of the body it covers. These two factors determine whether the injury will heal on its own or become life-threatening.

Burn Depth Classification

Burns are classified by how deeply they penetrate the skin layers. You do not need a medical degree to assess this --- the appearance, sensation, and blister characteristics tell you what you need to know.

First-Degree (Superficial)

What is damaged: Only the outermost layer of skin (epidermis).

What you see:

• Red skin, similar to a sunburn
• No blisters
• Skin blanches (turns white) when pressed, then returns to red

What the patient feels:

• Pain and tenderness to touch
• Mild to moderate burning sensation

Healing time: 3-7 days without scarring.

Example injuries: Brief contact with a hot pot, mild sunburn, quick splash of hot (not boiling) water.

Second-Degree (Partial Thickness)

What is damaged: The epidermis and part of the dermis (the thicker layer beneath containing nerves, blood vessels, and hair follicles).

What you see:

• Bright red or mottled red/white appearance
• Blisters --- ranging from small scattered ones to large fluid-filled sheets
• Wet, weeping surface when blisters break
• Skin may blanch when pressed

What the patient feels:

• Intense pain --- this is the most painful burn depth because nerve endings in the dermis are exposed but not destroyed
• Extreme sensitivity to air movement and temperature

Healing time: 2-4 weeks for superficial second-degree. Deep second-degree burns (extending further into the dermis) may take 4-8 weeks and will likely scar.

Example injuries: Scalding with boiling water, contact with hot metal for 1-3 seconds, close proximity to open flame.

The Tricky Distinction

Deep second-degree and third-degree burns can look similar in the first 24-48 hours. If the burn appears white or pale with reduced pain sensation, reassess after 48 hours. A burn that initially looks second-degree may “convert” to third-degree as damaged tissue dies over the following days. Always treat borderline burns as the more severe category.

Third-Degree (Full Thickness)

What is damaged: The entire epidermis and dermis are destroyed, possibly extending into fat, muscle, or bone.

What you see:

• White, waxy, leathery, or charred appearance
• No blisters (the skin structure is too damaged to form them)
• Skin does not blanch when pressed
• Visible blood vessels may be seen through the destroyed skin (thrombosed, appearing as dark lines)
• Hair pulls out easily from the area

What the patient feels:

• Paradoxically, little or no pain in the burn center because the nerve endings are destroyed
• Severe pain at the edges where the burn transitions to second-degree

Healing time: Cannot heal on its own except from the edges inward, which takes months and results in severe scarring and contracture. In modern medicine, these require skin grafts.

Example injuries: Prolonged contact with flame, immersion in boiling liquid, contact with molten metal, electrical burns.

Quick Reference Comparison

Feature	First-Degree	Second-Degree	Third-Degree
Color	Red	Red, mottled, pink	White, waxy, charred
Blisters	None	Yes	None
Moisture	Dry	Wet, weeping	Dry, leathery
Pain	Moderate	Severe	Minimal in center
Blanching	Yes	Yes	No
Texture	Normal	Soft, swollen	Firm, leathery
Healing	3-7 days	2-8 weeks	Months, with scarring

Estimating Burn Area: The Rule of Nines

Knowing what percentage of the body surface is burned is critical for determining fluid needs and predicting survival. The Rule of Nines divides the adult body into regions, each representing approximately 9% (or multiples of 9%) of total body surface area (TBSA).

Adult Body Surface Percentages

Body Region	Percentage
Head and neck	9%
Each arm (entire)	9%
Chest (front)	9%
Abdomen (front)	9%
Upper back	9%
Lower back	9%
Each upper leg (front and back)	9%
Each lower leg (front and back)	9%
Groin/perineum	1%
Total	100%

The Palm Method (For Irregular Burns)

For scattered or irregular burns that do not cover full body regions, use the patient’s own palm (fingers together) as a measuring unit. One palm equals approximately 1% of their body surface area.

Count how many palms would cover the burned area. This gives you the percentage.

Children Are Different

Children have proportionally larger heads and smaller legs than adults:

Region	Child Under 5	Adult
Head	18%	9%
Each leg	14%	18%

This matters for fluid calculations. A child’s head burn represents twice the body surface area of an adult’s.

Severity Classification by Area

Once you know the depth and area, classify the overall severity:

Minor burn --- can be managed with basic wound care:

• First-degree burn of any size
• Second-degree burn less than 10% TBSA in adults, less than 5% in children
• No third-degree involvement

Moderate burn --- requires dedicated caregiving and close monitoring:

• Second-degree burn 10-20% TBSA
• Third-degree burn less than 5% TBSA
• Burns on face, hands, feet, or joints (regardless of size)

Critical burn --- life-threatening, maximum survival effort needed:

• Second-degree burn greater than 20% TBSA
• Third-degree burn greater than 5% TBSA
• Burns involving airway (inhaled hot air or smoke)
• Circumferential burns (wrapping completely around a limb or the torso)
• Burns combined with other major trauma

Circumferential Burns

A burn that wraps entirely around a limb, finger, or the chest is especially dangerous. As the burned tissue swells, the inelastic damaged skin acts like a tourniquet, cutting off blood flow to everything beyond it. Check circulation beyond circumferential burns every hour --- feel for pulse, check for numbness, observe color. If circulation is compromised and no other help is available, the constricting burned tissue may need to be cut (escharotomy) to release pressure. This is a desperate measure but can save a limb or a life.

The 48-Hour Reassessment

Burns evolve over time. A burn that looks second-degree on day one may reveal itself as third-degree by day two or three as damaged cells die. Always reassess burns at:

• 6 hours --- initial swelling peaks, true extent becomes clearer.
• 24 hours --- blisters have fully formed, depth is more apparent.
• 48 hours --- final depth classification is usually possible.

During reassessment, look for:

• Areas that have lost sensation (deepening to third-degree)
• Blisters that have collapsed and revealed white or pale wound beds
• Increasing firmness or leathery texture
• Loss of blanching response

Document your findings each time. If the burn is worsening, increase the intensity of treatment accordingly.

Survival Statistics Without Modern Medicine

These numbers are harsh but important for making triage decisions when resources are limited:

Burn Severity	Survival Without Modern Care
Less than 10% TBSA, second-degree	Greater than 90% with good wound care
10-20% TBSA, second-degree	70-80% with aggressive fluid and wound management
20-40% TBSA, mixed depth	30-50% --- infection is the primary killer
Greater than 40% TBSA	Less than 10% --- focus on comfort care

These estimates assume clean water, honey or equivalent antimicrobial dressings, adequate food, and dedicated caregiving.

Key Takeaways

• Burn depth is determined by color, blisters, moisture, pain level, and blanching --- not by what caused it.
• Second-degree burns are the most painful; third-degree burns are paradoxically painless in the center.
• Use the Rule of Nines for large burns and the palm method for scattered burns to estimate body surface area.
• Always reassess at 48 hours --- burns can deepen as damaged tissue dies.
• Circumferential burns around a limb are an emergency requiring hourly circulation checks.