Pemphigus

• Blistering diseases
• Autoantibodies bind to desmosomal proteins -> cell adhesion disrupted -> vesicles
• Types:
  • Pemphigus vulgaris
    • Rare, severe form
    • Cats and dogs
    • Vesicles or bullae -> erosions and ulcers
    • Involves oral cavity, mucocutaneous junctions and skin
    • Microscopically:
      • Suprabasilar vesiculation and row of basal cells adhering to basement membrane
      • Superficial perivascular dermatitis
  • Pemphigus vegetans
    • Rare
    • Dogs
    • Involves the trunk
    • Mild version of P. vulgaris
    • Vesicopustular dermatitis + epidermal hyperplasia -> papillomatous formations
  • Pemphigus foliaceus
    • More common
    • Cats, dogs, horses, goats
    • Localised lesions or generalised
    • Symmetrical vesicular or pustular dermatitis, crusts, scales, alopecia
    • Microscopically:
      • Acantholytic cells
      • Subcorneal or intragranular pustules
      • In third of equine or canine cases eosinophils are predominant
  • Pemphigus erythematosus
    • Cats and dogs
    • Mild form of P. foliaceus
    • Usually involves only face and external ears