Pyotraumatic Dermatitis

• Also called acute moist dermatitis or 'hot spot'
• Common in dogs, especially self-inflicted due to pain and itching
• Usual causes: allergies, irritants, matted hair, parasites
• Lesions tend to be worse in hot and humid weather
• Grossly:
  • Hairless, red and moist lesion
  • Fluid exudate
  • Edges are circumscribed and red
• Microscopically:
  • Superficial erosive to ulcerative exudative dermatitis
  • May be deeper suppurative folliculitis