A 40-year-old man develops itchy pustules in the axillae and groin that evolve into foul-smelling vegetating plaques. Biopsy shows suprabasal acantholysis with intraepidermal eosinophilic microabscesses and marked pseudoepitheliomatous hyperplasia. Direct immunofluorescence shows intercellular IgG in a fishnet pattern. What is the diagnosis?
- A Pemphigus vegetans ✓
- B Pyoderma vegetans
- C Verrucous carcinoma
- D Chromoblastomycosis
Correct answer: A. Pemphigus vegetans
Explanation
Pemphigus vegetans is a rare variant of pemphigus vulgaris in which flexural vegetations develop; the Hallopeau type begins with grouped vesicopustules while the Neumann type arises from healing pemphigus vulgaris blisters. The combination of suprabasal acantholysis, eosinophilic intraepidermal abscesses, positive fishnet immunofluorescence, and intertriginous vegetations confirms the diagnosis. Pyoderma vegetans lacks acantholysis and immunofluorescence deposits, and verrucous carcinoma and deep fungal infection show no intercellular IgG pattern.
Reference: Bolognia, Dermatology, 5th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.