A 60-year-old man develops flaccid bullae on the trunk and oral erosions. Salt-split skin technique on patient's serum shows IgG binding exclusively to the ROOF (epidermal side). This pattern is most consistent with:

• A Bullous pemphigoid
• B Epidermolysis bullosa acquisita
• C Linear IgA bullous dermatosis
• D Pemphigus vulgaris ✓

Explanation

In the salt-split skin technique, artificial splitting occurs at the lamina lucida. Pemphigus vulgaris antibodies bind to the epidermal side (roof) because desmogleins are located within the epidermis. Bullous pemphigoid antibodies bind to the floor (dermal side). EBA antibodies also bind the floor. LABD shows a variable pattern but often floor binding. Pemphigus binding to the roof distinguishes it from all subepidermal blistering disorders.

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.