Mucosal-First Pemphigus Vulgaris With Delayed Generalized Bullous Eruption: A Case Report

Pemphigus vulgaris (PV) may initially present with persistent oral erosions and can be mistaken for infectious or inflammatory mucosal disease.

A previously healthy 43-year-old woman developed recurrent painful oral erosions that persisted despite multiple antifungal and antibacterial treatments. An initial biopsy from a necrotic oral ulcer was nondiagnostic. Following substantial oral improvement, she developed a generalized painful vesiculobullous eruption involving approximately 12% of the body surface area. Nikolsky sign was positive. Repeat skin biopsy demonstrated suprabasal acantholysis and blister formation, strongly supporting PV. She was treated with oral prednisolone 60 mg/day followed by a six-week taper, together with topical clobetasol. Cutaneous lesions had clinically cleared by approximately 25 August 2026. At follow-up on 7 September 2026, approximately 13 days after cutaneous clearance, no active oral or cutaneous lesions or documented recurrence were present.

This case highlights the diagnostic importance of appropriate biopsy-site selection in persistent oral erosions and the value of repeat biopsy from an active lesion. Because direct immunofluorescence and antidesmoglein serology were not performed, the diagnosis is best regarded as probable, histopathologically supported PV rather than immunopathologically confirmed PV.