DIFFUSE LUNG DISEASE OF UNKNOWN ETIOLOGY



Rheumatoid arthritis is associated with five dif­ferent pulmonary manifestations present in a high percentage of seropositive cases: exudative pleural effusion characterized by a very low glu­cose concentration; pulmonary nodules varying from a few millimeters to greater than 5 cm in diameter; rheumatoid nodules in association with coal workers’ pneumoconiosis (Caplan’s syn­drome); diffuse interstitial fibrosis; and pulmo­nary vasculitis. With the exception of the nodules and the low glucose in the pleural fluid, patients with systemic lupus erythematosus (SLE) may have many of the same manifestations. Pleuritis and pneumonitis have also been described in Sjo­gren’s syndrome, polymyositis, and dermato-myositis. The lung is commonly involved in scler­oderma presenting as pulmonary fibrosis and/or pulmonary hypertension.





DIFFUSE LUNG DISEASE OF UNKNOWN ETIOLOGY