Info
🌱 來自: Huppert’s Notes
Autoimmune Bullous Diseases🚧 施工中
Autoimmune Bullous Diseases
Bullous pemphigoid (BP)
• Pathophysiology: Chronic autoimmune blistering disease most commonly seen in the elderly due to autoantibodies targeting hemidesmosomes in the basement membrane, resulting in sub-epidermal blistering (“bullow”).
• Clinical features: Pruritic plaques and urticarial lesions with tense, intact blisters on the thighs and flexural areas
• Histology: Direct immunofluorescence (DIF) shows linear IgG deposition at the basement membrane zone
• Treatment: Topical high-potency glucocorticoids, oral steroids, methotrexate, mycophenolate mofetil
Pemphigus vulgaris
• Pathophysiology: Rare autoimmune blistering disease with mucocutaneous involvement due to autoantibodies targeting desmoglein proteins in the epidermis, resulting in suprabasal (interepidermal) blistering.
• Clinical features: Flaccid blisters that easily rupture (+Nikolsky sign) leaving painful, bright red erosions; most patients have oral involvement but can also see esophageal, urethral, vulvovaginal, and penile lesions
• Histology: DIF shows intracellular IgG deposition; may also see “tombstones” of basal cells attached to the basement membrane
• Treatment: Systemic steroids, azathioprine, or mycophenolate, plasmapheresis, cyclophosphamide, or rituximab for severe disease
Dermatitis herpetiformis
• Pathophysiology: Autoimmune blistering disease due to IgA autoantibodies targeting epidermal tissue transglutaminase; >90% of patients have gluten insensitivity
• Clinical features: Presents with severe pruritus and excoriated papulovesicles on the extensor surfaces (elbows, knees)
• Treatment: Gluten avoidance, dapsone