Vesiculobullous Diseases
Pemphigus Vulgaris
Autoimmune intraepithelial blistering disease with IgG autoantibodies against desmoglein-3 (and desmoglein-1).
§ overviewOverview
Autoimmune intraepithelial blistering disease with IgG autoantibodies against desmoglein-3 (and desmoglein-1).
§ etiologyEtiology
- 01Autoantibodies against desmoglein-3
- 02HLA-DR4 association
§ pathogenesisPathogenesis
IgG binds desmogleins → loss of keratinocyte adhesion (acantholysis) → intraepithelial suprabasal split.
§ clinicalClinical Features
- 01Oral lesions precede skin in 50–70%
- 02Flaccid bullae that rupture to painful erosions
- 03Positive Nikolsky sign
§ differentialDifferential Diagnosis
- 01Mucous membrane pemphigoid
- 02Erythema multiforme
- 03Paraneoplastic pemphigus
- 04Erosive lichen planus
§ histopathHistopathology
- 01Suprabasal intraepithelial split
- 02Tzanck cells (acantholytic keratinocytes)
- 03Basal cells attached to basement membrane ('row of tombstones')
§ investigationsInvestigations
- 01Direct immunofluorescence — intercellular IgG/C3 ('fish-net' pattern)
- 02Indirect IF — circulating antibodies
- 03ELISA — anti-desmoglein-3 titres
§ treatmentTreatment
- 01Systemic corticosteroids (prednisolone 1 mg/kg/day)
- 02Steroid-sparing: azathioprine, mycophenolate mofetil
- 03Rituximab (first-line in moderate-severe disease per current guidelines)
§ complicationsComplications
- 01Sepsis
- 02Fluid & electrolyte imbalance
- 03Steroid side effects
§ prognosisPrognosis
Untreated 80% mortality; with therapy 5–10%.
§ pearlsClinical Pearls
- 01Rituximab has revolutionised management — early referral is essential.
§ mnemonicsMnemonics
- 01Pemphigus = 'PV kills Deep' (Desmoglein-3, suprabasal)
Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.