In epidermolysis bullosa acquisita (EBA), which antigen is targeted and where does it localise on salt-split skin on indirect immunofluorescence?

• A BP180 (BPAG2); stains the roof (epidermal side) of salt-split skin
• B Desmoglein-3; stains the roof of salt-split skin
• C Laminin-332; stains the floor on salt-split skin
• D Type VII collagen; stains the floor (dermal side) of salt-split skin ✓

Explanation

EBA is caused by autoantibodies against type VII collagen, the major component of anchoring fibrils at the dermal-epidermal junction. On 1M NaCl salt-split skin, the cleavage occurs within the lamina lucida; type VII collagen is located in the sub-lamina densa (dermis), so EBA IIF stains the floor (dermal side) of the split. BP180 and BP230 antibodies in bullous pemphigoid stain the roof. This salt-split distinction is a classic NEET PG question.

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.