Restrictive lung disease due to diaphragmatic dysfunction in systemic lupus erythematosus. Two case reports.

Two patients with systemic lupus erythematosus and unexplained dyspnea are described. Both had severe dyspnea and a restrictive lung function pattern without any apparent specific pathology. Both patients initially responded to corticosteroids and/or immunosuppression; one patient, however, relapsed and eventually died. Many factors may contribute to this syndrome, including diaphragmatic dysfunction, splinting of the diaphragm, pleuritis, atelectasis and respiratory muscle dysfunction. This syndrome, which may respond to steroids or immunosuppressive treatment, must be considered in SLE patients with dyspnea lacking a concrete underlying cause.