Immunobullous dermatosis associated with Waldenström macroglobulinaemia treated with rituximab.

[waldenström macroglobulinemia]

Waldenström macroglobulinaemia (WM ) is a chronic lymphoproliferative disorder characterized by the presence of a monoclonal IgM paraprotein . Specific cutaneous features of WM include neoplastic cell infiltrates , IgM storage papules and IgM bullous dermatosis . We report a patient with subepidermal bullous disease associated with WM . Immunofluorescence identified IgM deposition along the basement membrane zone (BMZ ) with circulating anti-BMZ IgM antibodies reacting with the dermal side of salt -split skin . The autoantibodies did not react with type VII collagen or laminin 332 . Following failed treatment with doxycycline , prednisolone , intravenous immunoglobulin and dapsone , the patient was successfully treated with a modified RCVP regimen (rituximab , cyclophosphamide and prednisolone ). To our knowledge , this is the first reported case of IgM bullous disease of WM treated with rituximab .