Bacterial infections

• Bacterial infections


  Infections caused by bacteria that can circumvent the body's defenses and exploit its resources
• Pathogenic bacteria


  Bacteria that possess characteristics that enable them to spread by a variety of mechanisms
• A significant number of organisms must survive in the environment and reach a vulnerable host in order for it to spread
• Types of Skin Lesions

  • Macules
  • Papules
  • Plaques
  • Nodules
  • Urticaria (wheals or hives)
  • Vesicles
  • Bullae
  • Pustules
  • Purpura
  • Ulcer
  • Eschar
• Macules


  Flat lesions characterized by a change in color of the affected skin
• Papules


  Raised lesions, solid in consistency of less than 5 mm diameter
• Plaques


  Lesions with an elevated surface (plateau-like) with more than 5mm diameter
• Nodules


  Rounded raised lesions more than 5mm in diameter
• Urticaria (wheals or hives)

  Annular or ring-like papules or plaques with pinkish color
• Vesicles


  Circumscribed fluid-filled lesions less than 5mm in diameter
• Bullae


  Circumscribed fluid-filled lesions more than 5mm in diameter
• Pustules


  Circumscribed, exudate-filled lesions
• Purpura


  Skin lesions due to bleeding into the skin
• Types of Purpura


  • Petechiae (less than 3mm diameter)
  • Ecchymosis (more than 3mm diameter)
• Ulcer


  Crater-like lesion that may involve the deeper layers of the epidermis and dermis
• Eschar


  Necrotic ulcer covered with a blackened scab or crust