Coexistence of mucous membrane pemphigoid and connective-tissue disease.

Mucous membrane pemphigoid (MMP) is an autoimmune blistering disease that predominantly affects the mucosa. We report eight patients with MMP who also had systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), or both. Eight women (six white, two Hispanic; mean age of onset 53.5 years [range 44-68]) were studied. In four patients, both diseases were detected simultaneously, and in the other four patients, MMP preceded SLE or MCTD. MMP was widespread and resistant to conventional immunosuppressive therapy, but responded to intravenous immunoglobulin (IVIg). During a mean follow-up of 10.25 years (range 6-18), three patients had stable SLE/MCTD, whereas in the other five patients the SLE/MCTD required systemic corticosteroids either with or without immunosuppressive agents. Renal, serosal, pulmonary and neurological features were not observed in any patient. At the time of reporting, the MMP was in a prolonged sustained remission in all eight patients. The SLE/MCTD remained mild, did not involve vital organs and had continued with low-grade activity. In summary, we report the simultaneous occurrence of two rare diseases in a group of patients.