Extensive Flexural and Pan-Ungual Involvement in Hallopeau-Type Pemphigus Vegetans: A Case Report.

Pemphigus vegetans is a rare variant of pemphigus vulgaris characterized by vegetating plaques predominantly involving intertriginous areas. A 34-year-old woman presented with persistent painful oral lesions followed by progressive flexural, palmoplantar, and pan-ungual involvement. Examination revealed exuberant erosive vegetating plaques of the major folds, associated with oral erosions, palmoplantar pustules, and diffuse nail involvement. Histopathology showed papillomatosis, acanthosis, suprabasal cleavage, and acantholysis. Direct immunofluorescence demonstrated intercellular immunoglobulin G and complement C3 deposits, while indirect immunofluorescence detected circulating anti-intercellular substance antibodies, confirming Hallopeau-type pemphigus vegetans. Treatment with systemic corticosteroids and rituximab resulted in progressive healing of the cutaneous and mucosal lesions, with subsequent nail regrowth. This case highlights the importance of considering pemphigus vegetans in patients with vegetating lesions of the folds associated with mucosal involvement and extensive pan-ungual involvement, a rare but clinically distinctive feature of this disease.