A 45-year-old woman presents with flaccid blisters in the oral cavity and over the trunk for 2 months. Nikolsky sign is positive. DIF shows IgG and C3 in a chicken-wire (intercellular) pattern throughout the epidermis. Anti-desmoglein 3 antibodies are positive. What is the diagnosis?
- A Bullous pemphigoid
- B Dermatitis herpetiformis
- C Pemphigus vulgaris ✓
- D Pemphigus foliaceus
Correct answer: C. Pemphigus vulgaris
Explanation
Pemphigus vulgaris is the most common form of pemphigus, characterized by flaccid blisters, positive Nikolsky sign, and early mucosal involvement. Direct immunofluorescence shows IgG and C3 in a characteristic chicken-wire intercellular pattern due to antibodies against desmoglein 3 (and occasionally desmoglein 1). The suprabasal acantholysis results in fragile, easily ruptured blisters. Bullous pemphigoid shows linear IgG at the basement membrane zone and has tense blisters with negative Nikolsky sign.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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