ABSTRACT
I. Introduction The systemic autoimmune diseases are a heterogeneous group of inflammatory disorders that can affect the pleura with various frequencies either as single presenting feature or as part of multisystem involvement. Pleural disease in connective tissue disease occurs most frequently in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but there is a considerable variation in the reported prevalence, natural history, and treated course of pleural involvement in both diseases. The definition of pleural disease in other connective tissue disorders is necessarily imprecise. Many of the systemic diseases covered in this chapter are, themselves, rare, and pleural involvement is infrequent; thus, the spectrum of pleural disease is not captured in the medical literature to two standard deviations of disease behavior. It is foolhardy to attempt to generalize from single case reports or retrospective data from very small series.
