A 32-year-old man with active ulcerative colitis develops multiple small pustules on the buccal mucosa and gingiva that coalesce into raised vegetative plaques with a snail-track appearance. Biopsy shows intraepithelial and subepithelial microabscesses rich in neutrophils with scattered eosinophils. What is the most likely diagnosis?

• A Pemphigus vegetans
• B Pyostomatitis vegetans ✓
• C Oropharyngeal pyoderma gangrenosum
• D Major aphthous stomatitis

Explanation

Pyostomatitis vegetans is the oral counterpart of pyoderma gangrenosum and a highly specific marker of inflammatory bowel disease, classically ulcerative colitis. The snail-track pustules and neutrophilic microabscesses are characteristic. Pemphigus vegetans is killed by immunofluorescence: it shows intercellular IgG deposition, which is absent here, and it lacks the strong IBD association. Aphthae are recurrent discrete ulcers, not vegetative plaques.

Reference: Bolognia, Schaffer and Cerroni, Dermatology, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.