Erythema multiforme-like lip presentation in pemphigus vulgaris patients: a multicenter case series.

Pemphigus vulgaris (PV) is a chronic autoimmune mucocutaneous blistering disease. Autoantibodies are directed against desmogleins, leading to the formation of intraepithelial bullae. PV, as with other autoimmune mucocutaneous disorders of the oral cavity, presents diagnostic and therapeutic challenges. Approximately 50-70% of cases present first with oral lesions. The lesions commonly start as vesicles or bullae that rapidly rupture, leading to erosions and ulcerations. The palatal, gingival, buccal, and labial mucosa are the most commonly affected sites. Oral PV can mimic several other diseases that cause mucosal erosions and/or ulcerations, including erythema multiforme (EM). EM is an acute, immune-mediated, self-limited hypersensitivity condition primarily associated with herpes simplex infection. Oral lesions can be variable, but a very characteristic presentation with labial hemorrhagic erosions, ulcerations and crusting is commonly seen. In this case series, we present six cases of PV: one male patient and five female patients whose ages ranged from 34 to 65 years old. All patients presented with hemorrhage and crusting of the lips in addition to multiple intraoral erosions and ulcerations. Three patients presented with oral and skin lesions. All patients underwent biopsies, and a diagnosis of PV was confirmed. All patients were treated with steroids (topical and systemic) and variable steroid-sparing agents. This case series emphasizes that oral PV may be misdiagnosed as EM in a subgroup of patients who present with persistent lip hemorrhage and crusting. Therefore, a comprehensive history, clinical examination and incisional biopsies should be considered in such patients.