A 10-year-old child presents with large, flaccid bullae on normal-appearing skin, predominantly on the face, neck, and upper trunk. There is no mucosal involvement. Nikolsky sign is positive. Histopathology reveals acantholysis within the granular layer of the epidermis. The autoantigen targeted is:

• A Desmoglein 3
• B Desmoglein 1 ✓
• C Desmoplakin I and II
• D BP180 NC16A domain

Explanation

Pemphigus foliaceus (and its endemic variant, fogo selvagem) features autoantibodies against desmoglein 1, which is expressed predominantly in the superficial (granular) layer of the epidermis and is absent from mucosae. This explains the characteristic subcorneal/granular layer acantholysis, absence of mucosal involvement, and predominance on seborrhoeic areas. In contrast, pemphigus vulgaris targets desmoglein 3 (expressed in deeper epidermis and mucosae), causing suprabasal acantholysis with mucosal involvement. Desmoplakins are targeted in paraneoplastic pemphigus.

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.