Skin Structure and Wound Classification

Study Notes

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)

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.

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

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

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.