Lecture Notes: Skin Layers and Burns

Skin Structure

• Three Main Layers of Skin
  • Epidermis
  • Dermis
  • Hypodermis (Subcutaneous layer)

Burns: Types and Effects

• Definition: Tissue injuries caused by various factors (heat, chemicals, electricity, radiation, extreme cold, friction).

• Superficial Burns

  • Affect only the epidermis.
  • Cause erythema (redness) and pain.

• Partial Thickness Burns

  • Superficial Partial Thickness
    • Involve epidermis and upper (papillary) dermis.
    • Cause immediate blistering, intense pain, sensitivity.
  • Deep Partial Thickness
    • Destroy papillary dermis, epidermis, most of lower (reticular) dermis.
    • Some cutaneous nerve endings, capillaries, dermal appendages are spared.

• Full Thickness Burns

  • Destroy entire epidermis, dermis, and portions of hypodermis.
  • Burned area appears white, brown, dry, and charred.
  • No sensation, cannot heal without surgery.

Evaluating Burns

• Rule of Nines
  • Quick estimation of body surface area affected by burns.
  • Each body part assigned a value of 9% or a multiple of 9%.

Burn Complications

• Severe Burns
  • Increase capillary permeability.
  • Lead to two stages of shock:
    • Hypovolemic Shock
      • Loss of water, electrolytes, plasma proteins into interstitial spaces.
      • Causes widespread edema.
    • Burn Shock
      • Decreased intravascular volume increases blood viscosity, vascular resistance.
      • Heart rate increases to compensate.
      • Result in tissue and organ death due to lack of oxygen.

Burn Treatment

• Fluid Balance
  • Restore with intravenous fluids, electrolytes, proteins.
  • Increases intravascular volume.
• Wound Care
  • Prevent infection, promote healing.
  • Superficial Burns: Analgesics for pain and inflammation.
  • Superficial Partial Thickness Burns: Cleansed, covered with sterile dressing, monitored for infection.
  • Deep Partial Thickness Burns:
    • Dead skin (eschar) removed via debridement.
    • Wound bed kept clean, moist.
    • Prepares site for skin grafting.
  • Full Thickness Burns
    • Areas excised, regularly debrided.
    • Maintains viable base for grafting.