Table 1.
Classification of burn wound’s depth. Information from [4, 7, 9–11]
| First-degree | Second-degree | Third-degree | Fourth-degree | ||
|---|---|---|---|---|---|
| Depth of burn | Epidermis (superficial) | SPTB Epidermis and upper 1/3 dermis |
DPTB Epidermis and dermis, affecting appendages |
Full thickness (including subcutaneous fat) | Extends into muscle, tendons and/or bone |
| Histologic findings | Loss of epidermal attachment to dermis Epidermal cells with nuclear pyknosis (shrinkage) |
Loss of epidermal attachment to dermis Vacuolar cytoplasmic disintegration of the basal cell layer |
Coagulation of epidermis and dermis Denatured collagen appears swollen and basophilic Exudative infiltrate may be seen Loss of regenerative niches |
Carbonized surface with intense basophilic coagulated dermis. Scant epidermal/dermal cells present Loss of regenerative niches |
|
| Most common causes | Sunburn (prolonged UV exposure) | Brief contact with hot liquids, chemicals, flames or electric discharge (such as lightning) | Exposure to hot liquids, chemicals, flames or electric discharge | Prolonged time in direct contact with hot liquids, chemicals, flames or electric discharge | |
| Appearance | Dry burns with erythema and desquamation Absence of blisters Blanch with pressure |
Wet/weeping burns with erythema Blisters present Blanch with pressure |
Moist burns with erythema and a red-waxy white appearance Blisters present easily unroof Delayed blanch when pressure is applied |
Waxy white to dark-leathery dry and inelastic burns Do not blanch with pressure |
White or black burns Do not blanch with pressure |
| Sensation | Painful | Extremely painful | Painful only with pressure | Painless unless deep pressure is applied | |
| Healing time | 3–6 days | 7–14 days | >21 days, usually require surgical treatment | Require surgical treatment to start healing | |
| Scarring | No scarring observed | No scarring, but skin dyspigmentation is expected | Hypertrophic and keloid scarring expected with or without skin contracture | Hypertrophic and keloid scarring with severe skin contracture | |
SPTB superficial partial-thickness burns, DPTB deep partial-thickness burn