Pemphigus Vulgaris

Key points

• Pemphigus vulgaris: autoimmune (anti-desmoglein 3) intraepidermal blistering — FLACCID bullae that rupture easily, positive Nikolsky's sign, painful oral erosions (often first).
• Potentially life-threatening without treatment.
• Diagnosis: skin biopsy + direct immunofluorescence (intercellular IgG/'chicken-wire').
• Management: high-dose oral steroids + steroid-sparing immunosuppressants (azathioprine, rituximab).
• Paraneoplastic pemphigus associated with lymphoma/thymoma.