Mucosal involvement in pemphigus foliaceus: A rare presentation

Abstract

Pemphigus foliaceus (PF) is a rare autoimmune blistering disorder characterized by antibodies targeting desmoglein 1 (Dsg1), a critical adhesion protein in the upper epidermis. Mucosal involvement is typically absent due to the protective expression of desmoglein 3 (Dsg3) in mucous membranes. However, rare cases challenge this paradigm, indicating the potential for atypical presentations. We report a 62-year-old woman with type 2 diabetes who presented with chronic, painful erosions of the oral mucosa, followed by development of erosive cutaneous lesions. Histopathology and direct immunofluorescence confirmed the diagnosis of PF, and ELISA identified circulating anti-Dsg1 antibodies in the absence of anti-Dsg3. Treatment with systemic corticosteroids and rituximab led to rapid skin improvement, though a subsequent relapse of isolated oral lesions occurred. Colchicine therapy provided significant and sustained relief. This case highlights the rare but significant potential for mucosal involvement in PF, possibly due to high autoantibody titers or chronic inflammation compromising mucosal integrity. It underscores the need for clinicians to include PF in the differential diagnosis of persistent oral erosions and to consider adjunctive treatments like colchicine for refractory mucosal disease. A tailored, multimodal approach can effectively manage both cutaneous and mucosal manifestations in such atypical presentations.