Skin Structure and Wound Classification

Skin: structure and function

• The skin is the largest organ of the body.
• The primary function of the skin is protection.
• The skin has several layers:
  • Outer epidermis
  • Dermis, containing the capillary network
  • Subcutaneous layer (hypodermis, adipose layer)

Skin: structure and function (cont.)

• The thickness of the skin varies, from thin at internal flexures (e.g. elbows) to thicker at the soles of the feet.
• Hair follicles, sebaceous glands, and sweat glands pass through the epidermis, but originate in the dermal layer.

Wounds

• A wound is a cut or break in the continuity of any tissue, caused by injury or operation.

Classifying Wounds

• Wounds may be classified according to the number of skin layers involved:
  • Superficial: Involves only the epidermis
  • Partial Thickness: Involves the epidermis and the dermis
  • Full Thickness: Involves the epidermis, dermis, fat, fascia, and exposes bone

Types of Wounds

• Closed Wounds (Blunt Injuries):

  • Abrasions: partial denusion of the superficial layers of skin due to friction against a rough surface.
    • Clinical Presentation (C/P): Painful raw surface.
    • Treatment (ttt): Antibiotic, daily dressing
  • Contusion (ecchymosis): extravasations of blood, plasma through damaged blood vessels.
    • C/P: Painful swelling, ecchymotic skin.
    • ttt: Fomentation (cold in the first 24 hours), elevation.

• Open Wound:

  • Incised Wound: Made by a sharp instrument.
    • Tissue Damage: little or no tissue damage
    • Edges: Clean cut
    • Bleeding: Severe bleeding
    • Infection: No infection
  • Lacerated Wounds: Made by a blunt instrument.
    • Tissue Damage: Severe damage
    • Edges: Crushed
    • Bleeding: Little bleeding
    • Infection: Liable for infection
  • Crushed Wound: More extensive lacerated wound caused by war injuries.
  • Penetrating Wound:
    • Perforating: Has an inlet and outlet.
    • Punctures: Only an inlet.