Which immunobullous disorder shows 'n-serrated' pattern on electron microscopy of the BMZ, distinguishing it from bullous pemphigoid which shows 'u-serrated' pattern?

• A Pemphigus vulgaris
• B Dermatitis herpetiformis
• C Linear IgA disease
• D Epidermolysis bullosa acquisita ✓

Explanation

Epidermolysis bullosa acquisita (EBA) targets type VII collagen in the sub-lamina densa (anchoring fibrils). On salt-split skin (1M NaCl), DIF in EBA shows IgG on the dermal floor, while bullous pemphigoid deposits on the epidermal roof. On electron microscopy, EBA shows n-serrated (narrow) deposits below the lamina densa, whereas BP shows u-serrated (undulating) deposits in the lamina lucida/lucida area.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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