A 55-year-old woman presents with flaccid blisters that rupture easily leaving raw, painful erosions on her trunk and oral mucosa. Nikolsky sign is positive. Direct immunofluorescence (DIF) of perilesional skin shows IgG and C3 deposits in a fishnet/chicken-wire pattern throughout the epidermis. What is the target antigen?
- A BP180 (type XVII collagen) and BP230
- B Laminin 332 (epiligrin)
- C Desmoglein 3 (and sometimes desmoglein 1) ✓
- D Type VII collagen (anchoring fibrils)
Explanation
Pemphigus vulgaris is characterised by autoantibodies (IgG) against desmogleins — transmembrane desmosomal cadherins. In mucocutaneous pemphigus vulgaris, autoantibodies target primarily desmoglein 3 (mucosal) and secondarily desmoglein 1 (cutaneous), causing acantholysis (loss of keratinocyte-to-keratinocyte adhesion). DIF shows the classic intercellular 'chicken-wire' or 'fishnet' IgG ± C3 staining throughout the epidermis. BP180 and BP230 are targets in bullous pemphigoid. Laminin 332 is targeted in mucous membrane pemphigoid. Type VII collagen is targeted in epidermolysis bullosa acquisita.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.