A middle-aged man presents with flaccid blisters and leafy crusts over the seborrhoeic areas of the face and trunk. Direct immunofluorescence of perilesional skin shows intercellular IgG deposition restricted to the upper epidermis, sparing the basal layers. Which antigen is targeted by these antibodies?

• A Envoplakin
• B Desmoglein 3
• C Desmoglein 1 ✓
• D Type VII collagen

Explanation

Pemphigus foliaceus features autoantibodies against desmoglein 1, the desmosomal cadherin expressed predominantly in the superficial epidermis, producing subcorneal acantholysis and upper-epidermal intercellular staining on DIF. The best distractor is desmoglein 3, the dominant target in pemphigus vulgaris, where antibodies bind mainly mucosal stratified squamous epithelium rich in Dsg3; isolated anti-Dsg1 disease spares mucosa because Dsg3 compensates there.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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