Paraneoplastic pemphigus triggered by radiotherapy.

Paraneoplastic pemphigus is a recently described autoimmune disease characterized by painful mucosal ulceration and polymorphous skin lesions in association with an underlying neoplasm. Distinct autoantibodies bind desmoplakin I, desmoplakin II, bullous pemphigoid antigen and an uncharacterized 190 kDa antigen. A case is presented of paraneoplastic pemphigus that developed after radiotherapy for non-Hodgkin's lymphoma in a 53 year old man. Multiple skin biopsies showed a lichenoid reaction without acantholysis. Immunofluorescence and mucosal biopsies were required to establish the correct diagnosis. Corneal opacities resembling lichenoid graft-versus-host disease and retinal haemorrhages, which developed in the patient, have not been previously documented. Despite high doses of immunosuppressive agents and plasmaphoresis, the patient eventually died from respiratory failure.