In bullous pemphigoid, indirect immunofluorescence using salt-split skin shows IgG deposits on the:
- A Epidermal side of the split ✓
- B Dermal side of the split
- C Both sides equally
- D Neither side — DIF is negative in salt-split preparation
Correct answer: A. Epidermal side of the split
Explanation
In the salt-split skin technique, NaCl splits the lamina lucida, placing hemidesmosomal antigens (BP180/BP230) on the epidermal side. IgG in bullous pemphigoid therefore deposits on the epidermal (roof) side of the split. In contrast, epidermolysis bullosa acquisita (anti-collagen VII, dermal side) and anti-p200 pemphigoid show dermal-side deposits, making this technique invaluable for subepidermal blister subtyping.
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.