Pemphigus vulgaris

Background

• Blistering skin condition of unknown etiology grouped with other forms of pemphigus
• Associated with autoantibodies targeting cadherins

Drug-Induced

• Penicillamine and captopril
• NSAIDs, penicillin, and cephalosporins
• Possibly certain foods, though mostly anecdotal

Clinical Manifestations

• Initially presents in oral mucosa in 80% of cases, and involves mucosa at some point in essentially all cases
  • Erosions on buccal mucosa, palate, tongue, and inner lips
  • Erosions and enanthema on gingiva
  • Pain varies from mild to severe
• Can involve other parts of the upper respiratory tract, including nose (with crusting) and larynx (with hoarseness)
• Other mucosal surfaces can be involved as well
• Cutaneous lesions
• Lesions are bullae that rupture leaving painful erosions
• Nikolsky sign may be present, where blisters form at sites of minor pressure or minor trauma

Diagnosis

• Based on clinical, histopathological, and laboratory evidence
• Skin biopsy is helpful
  • Direct immunofluorescence can show net-like or chicken-wire pattern of IgG on the epidermis
  • Tzanck smear shows acantholysis

Management

• Systemic corticosteroids with prednisone 1 mg/kg daily
• For more severe disease, add rituximab 2 x 1 g IV or azathrioprine or mycophenolate
• For treatment failure, increase prednisone dose, add rituximab (if not already using), add IVIG 2 g/kg over 2 to 5 days every 4 to 6 weeks, or try pulse steroids