Clinical perspective and practices on pleural effusions in chronic systemic inflammatory diseases

Systemic inflammatory diseases are a heterogeneous family of autoimmune chronic inflammatory disorders that affect multiple systems within the human body. Connective tissue disease (CTD) is a large group within this family characterised by immune-mediated inflammation of the connective tissue. This group of disorders are often associated with pleural manifestations. CTD-induced pleuritis exhibits a wide variety of symptoms and signs including exudative pleural effusions and chest pain. Accurate estimation of prevalence for CTD-related pleuritis is challenging as small effusions are asymptomatic and remain undetected. Rheumatoid arthritis and systemic lupus erythematosus are frequent CTDs and present with pleural pathology in approximately 5–20% and 17–60% of cases, respectively. By contrast, pleural involvement in systemic sclerosis, eosinophilia–myalgia syndrome, mixed connective tissue disease, ankylosing spondylitis, polymyositis and dermatomyositis syndrome is rare. Clinical management depends on the severity of symptoms; however, most effusions resolve spontaneously. In this review we discuss the pathophysiological mechanisms and the clinical considerations of CTD-induced pleuritis.