A burn is damage to the skin and sometimes to the underlying tissues. Burns are categorized according to the depth and extent of the damage to the skin:

  • Superficial burn (also called first-degree burn)
    • Mildest type of burn
    • Often caused by ultraviolet light, or very short (“flash") flame exposure
    • Affects only the outer layer of the skin (epidermis)
    • Normally does not cause scarring
    • Takes about 3-6 days to heal
  • Superficial partial-thickness burn (also called second-degree burn)
    • Often caused by a scald (spill or splash) or short (“flash”) flame exposure
    • Affects the outer layer of the skin more deeply, usually causing blistering
    • May or may not cause scarring, but often does cause long-term skin color changes
    • Takes about 1-3 weeks to heal
  • Deep partial-thickness burn (also called second-degree burn)
    • Often caused by a scald (spill), may involve flame, oil, or grease
    • Affects the outer and underlying layer of skin (dermis), causing blistering
    • Usually causes scarring
    • Usually takes more than three weeks to heal
  • Full-thickness burn (also called third-degree burn)
    • Very serious
    • Often caused by scald (immersion), may involve flame, steam, oil, grease, chemicals, or high-voltage electricity
    • Damages all layers of the skin, and may involve the tissues underneath (muscle and bone)
    • Causes scarring
    • Will heal only at the wound edges by scarring, unless skin grafting is done

Classification of Skin Burns
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Burns can be caused by:

  • Heat or flame (thermal burns)
    • Hot foods or drinks such as boiling water, tea, or coffee
    • Hot oil or grease
    • Hot tap water
    • Direct heat such as stoves, heaters, or curling irons
    • Direct flame
    • Flammable liquids such as gasoline
    • Fireworks
  • Chemicals (chemical burn)—strong acids or strong bases such as:
    • Cleaning products
    • Battery fluid
    • Pool chemicals
    • Drain cleaners
  • Sunlight (sunburn) or tanning beds
  • Electricity (electrical burn)
    • Damaged electrical cords
    • Electrical outlets
    • High-voltage wires
    • Lightning
  • Radiation (radiation burn)