A9. Autoimmune bullous skin diseases

From greek.doctor

Bullous pemphigoid

  • In elderly
  • Benign disease, responds well to treatment
  • Most common autoimmune bullous disease
  • Pathomechanism
    • Autoantibodies against hemidesmosomes
  • Clinical features
    • Prodromal stage
      • Weeks before onset of blistering
      • Urticarial lesions
    • Large, tense, subepidermal bulla
      • Don’t rupture easily
    • Intensely pruritic
    • Lower limbs, axilla
    • Rarely oral involvement
  • Diagnosis
    • Negative Nikolsky
    • Histology and immunofluorescence
  • Treatment
    • Prednisone (0,5 – 1 mg/bwkg)
    • Azathioprine, immunosuppressants

Pemphigus vulgaris

  • In middle-aged, elderly
  • Deadly without treatment
  • Pathomechanism
    • Autoantibodies against desmosomes
    • Acantholysis – loss of cell-cell adhesion
  • Clinical features
    • Painful, flaccid, intraepidermal (superficial) blisters
    • -> lesions rupture
    • -> erosions and crusts
    • -> re-epithelialization with hyperpigmentation but no scarring
    • No pruritus
    • Lesions often begin in oral mucosa then to body parts exposed to pressure
  • Diagnosis
    • Positive Nikolsky – Skin comes off with scraping
    • Histology and immunofluorescence
  • Treatment
    • High-dose prednisone (1-2 mg/bwkg)
    • Azathioprine, other immunosuppressants

Dermatitis herpetiformis

  • In young adults
  • Risk factors
    • Coeliac disease
    • Iodide sensitivity
    • HLA-DR3
    • HLA-DQ2
  • Pathomechanism
    • Tissue transglutaminase and epidermal transglutaminase antibodies
  • Clinical features
    • Chronic, recurrent
    • Tense, grouped, subepidermal vesicles
      • Herpetiform appearance, hence the name
    • Intensely pruritic
    • Bilateral, symmetrical distribution
      • Elbows, knees
    • No mucosal involvement
  • Diagnosis
    • Coeliac antibodies
    • Histology and immunofluorescence
  • Treatment
    • Dapsone
    • Gluten-free diet

Epidermolysis bullosa

  • Group of disorders where subepidermal blisters form following trauma
  • Not autoimmune
  • Epidermolysis bullosa simplex
  • Junctional epidermolysis bullosa
  • Dystrophic epidermolysis bullosa
  • Epidermolysis bullosa acquisita