Pemphigus Vulgaris
Pemphigus Vulgaris (PV) is a severe, life-threatening autoimmune blistering disease. It is caused by IgG autoantibodies against desmoglein 1 and 3, which are proteins involved in cell-to-cell adhesion (desmosomes) in the epidermis.
Clinical Presentation
- Oral Involvement: Often the initial site of presentation; painful, erosive lesions that are slow to heal.
- Cutaneous Lesions: Flaccid (soft) bullae that rupture easily, leaving raw, painful erosions.
- Nikolsky Sign: Positive; epidermis slides off with lateral pressure due to intraepidermal cleavage.
Diagnostic Criteria
| Test | Finding |
|---|---|
| Histopathology | Acantholysis (separation of keratinocytes); “row of tombstones” appearance. |
| Immunofluorescence | “Fishnet” pattern of IgG/C3 deposits in the intercellular space. |
High-Yield Exam Pearl:
- Comparison: Pemphigus Vulgaris (intraepidermal, +Nikolsky) vs. Bullous Pemphigoid (subepidermal, -Nikolsky, usually spares mucosa).
- Management: First-line therapy is high-dose systemic corticosteroids, often combined with steroid-sparing immunosuppressants (like Rituximab).