A 55-year-old woman presents with flaccid blisters on normal-appearing skin. Biopsy shows intraepidermal acantholytic blister with 'tombstone' appearance of basal keratinocytes. Immunofluorescence shows IgG and C3 deposition in a 'chicken-wire' pattern. The target antigen is located in which layer?
- A Lamina lucida of basement membrane
- B Desmoglein-1 in the granular layer
- C Desmoglein-3 in the spinous layer ✓
- D Laminin-332 in the lamina densa
Correct answer: C. Desmoglein-3 in the spinous layer
Explanation
Pemphigus vulgaris targets Desmoglein-3 (found predominantly in lower spinous and basal layers), causing loss of adhesion in the suprabasal zone; basal cells remain attached to the basement membrane, creating the 'tombstone row' sign. DIF shows IgG in an intercellular 'chicken-wire' pattern throughout the epidermis. Desmoglein-1 is the target in pemphigus foliaceus (superficial blistering). Lamina lucida antigens (BPAG2/BP180) are targets in bullous pemphigoid. Laminin-332 is targeted in cicatricial pemphigoid/mucous membrane pemphigoid.
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.