1.2.5 Pemphigus Vulgaris
Grading & Level of Importance: C
Incidence of 2-7 new cases per million per year. F = M, 30-60 years. Ethnic variations.
Autoimmune disease with intraepidermal blister formation.
Aetiology & Pathogenesis
Loss of cell adhesion within epidermis (Acantholysis) and blister formation by circulating autoantibodies against desmosomal proteins (desmogleins 1 and 3).
Signs & Symptoms
Pemphigus vulgaris: onset with oral erosions in more than 50% of cases, later superficial, fragile blisters with rapid transition to crusted erosions. The lesions usually develop in non-inflamed skin. Nikolski's signs positive (Nikolski I: blisters induced by rubbing normal skin. Nikolski II: existing blisters extend with lateral pressure). Pemphigus foliaceus: It manifests with impetigo-like crusted erosions usually on an erythematous base, and usually starts in seborrheic areas. Mucosae are usually spared.
Oral mucosae and entire skin surface, especially head, neck and trunk.
- Pemphigus vulgaris: target antigens desmoglein 3 and desmoglein 1, suprabasal blister formation. Rare variants include neonatal pemphigus, pemphigus vegetans.
- Pemphigus foliaceus: target antigen desmoglein 1, subcorneal blister formation.
- Fogo selvagem (Brazilian pemphigus): endemic form of pemphigus foliaceus in Brazil, black flies (Simulium) may be vectors.
- Pemphigus erythematosus: pemphigus foliaceus with positive ANA and photosensitivity.
- Paraneoplastic pemphigus: autoantibodies against both intraepidermal and subepidermal attachment proteins. Intraepidermal and subepidermal blister formation.
- IgA pemphigus.
- Pemphigus herpetiformis.
Laboratory & other workups
Direct immunofluorescence (DIF): identification of in vivo bound intraepidermal, intercellular autoantibodies in the skin biopsy. Indirect immunofluorescence (IIF): identification in patient's serum of circulating autoantibodies against stratified squamous epithelium. ELISA for detection of anti-desmoglein 1 and 3 an autoantibodies in serum.
Intraepidermal clefts secondary to acantholysis.
Chronic, progressive. If untreated may be fatal.
Before the introduction of systemic corticosteroids, high mortality rate (skin-related sepsis, marasmus secondary to fluid and protein loss, difficulty in eating). Today complications secondary to high-dose corticosteroids and other immunosuppressive therapy.
Tzanck test: direct identification of acantholytic cells in smear of blister content (smear, Giemsa stain). Histology (acantholysis). DIF: intraepidermal intercellular IgG deposits. IIF: circulating IgG, which binds to stratified squamous epithelium in intercellular pattern. Immunoblot/ELISA: antibodies anti-desmoglein 1 and 3 autoantibodies in serum.
- Mucosal and erosive oral lesions: acute herpetic stomatitis, aphthous stomatitis, erosive lichen planus, erythema multiforme major/Stevens-Johnson syndrome.
- Skin lesions: other autoimmune bullous diseases, erythema multiforme, Hailey-Hailey disease, staphylococcal scalded skin syndrome (SSSS), toxic epidermal necrolysis (TEN).
Prevention & Therapy
Systemic: rituximab, long-term immunosuppressive therapy (corticosteroids, azathioprine, methotrexate, dapsone, cyclophosphamide). In refractory cases: High dose intravenous immunoglobulins. Topical: general wound care.
Further Images / DOIA
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