Burns can be classified into:
Superficial (first degree): involves only the superficial epidermis; 3-7 days to heal with no scarring
Superficial partial-thickness (second degree): involves the epidermis and varying depths of dermis but not the hair follicles, sweat glands or sebaceous glands; heal in less than 21 days with minimal scarring
Deep partial-thickness (second degree): involves epidermis and dermis; more than 21 days to heal and may develop severe scarring
Full thickness (third degree): involves total destruction of the epidermis, dermis, hypodermis and may involve additional tissue; presents as charred painless surface known as an eschar; may require skin grafting
Deep full thickness (fourth degree): involves fat, nerve endings, muscle, and/or bone; may require flap coverage
The rule of 9s is used to calculate the body percentage of burns, for Total Body Surface Area (TBSA). Minor burns are under 15% TBSA. Moderate burns are 15-25% TBSA. Major burns are over 25% TBSA. For example, almost all electrical burns are classified as full thickness burns.
Burn complications can include:
Contractures (shortening of muscles, tendons, joint capsule)
Hypertrophic scars with disfigurement
Pruritus usually during first year post burn
Eye injuries, especially ectropion (invert, prevent eye closing)
Loss of facial members (nose, ears)
Hair loss (usually from full thickness burn)
Functional disabilities include:
Physical: functional impairments will not progress over time; contractures can reduce range of motion, but be improved with physical therapy or reconstructive or orthopedic surgery
Psychosocial: depression is common early in the healing process, but outlook is positive later on
Complications in the acute phase:
Smoke inhalation, lung injury
Sepsis due to necrotic tissue, bacterial infection
Urinary tract infection from catheter contamination
Gastrointestinal issues from nasal feeding tubes
Toxic exposures from fire/fumes, chemicals
Complications in the post-acute phase:
Contractures: may require dynamic splinting, serial casting, ultrasound diathermy, and may be permanent
Hypertrophic scars: can be reduced by pressure over the healing burn area compressive dressing, elasticized garments and after skin grafting. May require reconstructive surgery.