Sustained clinical response to rituximab in a case of life-threatening overlap subepidermal autoimmune blistering disease

The conventional treatment for the autoimmune bullous skin diseases is broad-spectrum immunosuppressive regimen typically combining systemic corticosteroids with adjuvant immunosuppressive therapeutic agents. Orphan diseases in the pemphigus, pemphigoid, and epidermolysis bullosa acquisita groups of clinical disorders are often clinically severe, requiring long-term treatment with such drugs or drug combinations. Rituximab, a chimeric recombinant monoclonal antibody targeting CD20((+)) B cells, has recently been suggested to be effective in the treatment of pemphigus with relatively few adverse effects. The clinical value of rituximab in other immune-mediated blistering diseases has been less thoroughly examined. We report a case of a woman who presented initially with the Brunsting-Perry phenotype of cicatricial pemphigoid who subsequently developed severe generalized subepidermal blisters healing with scarring and milia formation thought to be clinically compatible with epidermolysis bullosa acquisita, although type VII collagen autoantibodies were never identified. Treatment with a number of conventional systemic agents was unsuccessful and complicated by methicillin-resistant Staphylococcus-aureus induced cutaneous ulcers and near-fatal gram-negative sepsis. This woman has enjoyed an 18-month complete clinical remission after a single inductive 4-week cycle of intravenous rituximab. This outcome supports the idea that systemic memory B-cell depletion with drugs such as rituximab should be considered for therapeutically refractory subepidermal autoimmune blistering diseases in addition to intraepidermal autoimmune blistering diseases. A potential role for the immunologic phenomenon of epitope spreading in the generation of overlapping features of autoimmune blistering diseases, and its contribution to therapeutic refractoriness ("hardening"), is discussed. (J Am Acad Dermatol 2011;64:773-8.)