Dermatologic rituximab dosing: treatment of refractory pemphigus vulgaris in an adolescent male.

Rituximab is a chimeric monoclonal antibody against CD20 that mediates B-cell depletion. It has been shown to be effective in a variety of autoimmune-related diseases, including pemphigus vulgaris. Most reports of pemphigus treatment utilize the weekly dosing regimen designed for the treatment of B-cell malignancy. The authors report a case of successful treatment of refractory pemphigus vulgaris in an adolescent male using three infusions of rituximab spread over a four-month period of time. The authors also discuss recent updates in rituximab's mechanism of action in autoimmune disease. Rituximab acts to destroy auto-reactive B-cells prior to their development into auto-antibody producing plasma cells. More recent reports have shown that rituximab also indirectly leads to a decrease of autoreactive CD4+ T cells via depletion of B-cells that are necessary for antigen presentation. Monthly to bi-monthly rituximab infusion dosing may be a more appropriate dosing strategy for autoimmune disease that minimizes potential side effects while generating remission of disease. Dermatology continues to see an increase in use of medications designed for treatment of rheumatologic disease and malignancy. Additional studies should focus on the appropriate dosing of these medications for dermatologic conditions that limit the risk of adverse effects while preserving therapeutic benefit.