A 25-year-old woman with known SLE develops tense vesicles and bullae on sun-exposed skin. Biopsy shows a subepidermal blister packed with neutrophils, and direct immunofluorescence shows granular IgG at the basement membrane zone. The target antigen is:

• A Type VII collagen ✓
• B BP180 (type XVII collagen)
• C Desmoglein 3
• D Type IV collagen

Explanation

Bullous systemic lupus erythematosus is caused by autoantibodies to type VII collagen, the anchoring fibril protein of the sublamina densa. It presents as a widespread neutrophilic subepidermal blistering eruption in active SLE and characteristically responds rapidly to dapsone. BP180 is the antigen in bullous pemphigoid, desmoglein 3 in pemphigus vulgaris, and type IV collagen in anti-GBM disease.

Reference: Fitzpatrick's Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.