Treatment of pemphigus vegetans with rituximab: A case report and review of the literature

Pemphigus vegetans is a rare variant of pemphigus vulgaris. The incidence has been variably reported in the literature, ranging from 1-7% of patients with pemphigus vulgaris. Pemphigus vegetans is characterised by vegetating cutaneous lesions involving the intertriginous areas and invariably, the oral mucosal surfaces. Histopathology demonstrates hyperacanthosis, papillomatosis and suprabasal acantholysis. Direct immunofluorescence is identical to that of pemphigus vulgaris. Standard therapy consists of systemic corticosteroids and immunosuppressive agents. Rituximab, a monoclonal antibody directed against the CD20 antigen expressed on B lymphocytes, is used for refractory disease. The efficacy of rituximab has recently been demonstrated in patients with pemphigus vulgaris; however, its efficacy specifically in the subset of patients with pemphigus vegetans is not well-described. Herein we report a case of a 47-year-old woman with a 15-year history of pemphigus vegetans. Histopathology demonstrated a well-developed suprabasal acanthyolysis with extensive eosinophilic spongiosis; direct immunofluorescence showed patchy basement membrane staining with IgG and C3. Despite treatment with topical clobetasol proprionate with Daktarin, oral prednisolone and mycophenolate mofetil, she continued to experience disease flares. She experienced a flare characterised by severe oral mucosal erosions and hypertrophic plaques and large erosions in her axillae and inframammary folds, which required two doses of rituximab 500mg. She had a complete response with resolution of her cutaneous and mucosal lesions. Unfortunately, relapse occurred after six-months of remission. The short- and long-term efficacy of rituximab in patients with pemphigus vegetans merits further research and subgroup analysis in larger observational cohort studies of patients with pemphigus vulgaris is encouraged.

Dr. Nikki Adler