Patients with rheumatoid arthritis (RA) have an increased incidence of pleural effusion. In a review of 516 patients with RA, Walker and Wright (1) found 17 cases of pleural effusions (3.3%) without other obvious causes (1). Pleural effusions were more common in men (7.9%) than in women (1.6%). These authors also found a high incidence of chest pain in their patients with RA; 28% of the men and 18% of the women gave a history of pleuritic chest pain (1). In a separate study, Horler and Thompson (2) studied 180 patients with rheumatoid disease and found that 9 (5%) had an otherwise unexplained pleural effusion. In this latter study, 8 of 52 men (15%) but only 1 of 128 women (1%) had rheumatoid pleural effusions.

Examination of the pleural surfaces in patients with rheumatoid pleuritis at the time of thoracoscopy reveals a visceral pleura with varying degrees of nonspecific inflammation. In contrast, in most cases the parietal pleural surface has a “gritty” or frozen appearance. The parietal surface looks slightly inflamed and thickened, with numerous small vesicles or granules approximately 0.5 mm in diameter (3).

Histopathologically, the most constant finding is a lack of a normal mesothelial cell covering (3). Instead there is a pseudostratified layer of epithelioid cells that focally forms multinucleated giant cells of a type different from those of Langerhans or foreign body giant cells (3). The histologic features in nodular areas are those of a rheumatoid nodule with palisading cells, fibrinoid necrosis, and both lymphocytes and plasma cells (4,5). This picture is virtually diagnostic of rheumatoid pleuritis. However, even with tissue obtained from open thoracotomy, this specific histologic picture may not be seen (6). At times, the thickened pleura contains cholesterol clefts (5).

Rheumatoid pleural effusions classically occur in the older male patient with RA and subcutaneous nodules. Almost all patients with rheumatoid pleural effusions are older than 35 years of age, approximately 80% are men, and approximately 80% have subcutaneous nodules (1,2,6,7). Typically, the pleural effusion appears when the arthritis has been present for several years. When two series totaling 29 patients are combined (1,7), the pleural effusion preceded the development of arthritis in 2 patients by 6 weeks and 6 months, occurred simultaneously (within 4 weeks) with arthritis in 6 patients, and occurred after the development of arthritis in the remaining 21 patients. In this last group of patients, the mean interval between the development of arthritis and the pleural effusion was approximately 10 years.

The reported frequency of chest symptoms in patients with rheumatoid pleural effusions has varied markedly from one series to another. In one series of 24 patients, 50% of the patients had no symptoms referable to the chest (8). In a second series of 17 patients,
15 complained of pleuritic chest pain (1), whereas in a third series, 4 of 12 complained of pleuritic chest pain, and of these, 3 were febrile (7). Other patients complained of dyspnea secondary to the presence of fluid. In one reported patient, the pleural effusion was large enough to cause respiratory failure (9).

The chest radiograph in most patients reveals a small-to-moderate-sized pleural effusion occupying less than 50% of the hemithorax (Fig. 21.1). The pleural effusion is most commonly unilateral, and no predilection exists for either side (6). In approximately 25% of patients, the effusion is bilateral (1). The effusion may eventually alternate from one side to the other or may come and go on the same side. As many as one third of these patients may have associated intrapulmonary manifestations of RA (1). PET scans of patients with rheumatoid pleuritis show intense pleural uptake (10).

The natural history of rheumatoid pleuritis is variable. In the series of Walker and Wright (1), 13 of 17 patients (76%) had spontaneous resolution of their pleural effusions within 3 months, although 1 of the 13 patients had a subsequent recurrence. One patient had a spontaneous resolution after 18 months of observation, whereas another had a persistent effusion for more than 2 years. One patient developed progressive severe pleural thickening and eventually had to undergo a decortication. The last patient developed an empyema.

Little information is available in the literature on the efficacy of therapy in rheumatoid pleural disease. Some patients have appeared to respond to systemic corticosteroids (1), whereas in others no beneficial effects were observed (20,21,22). The degree of activity in the pleural space and in the joints is not necessarily parallel. In one report, the administration of methotrexate was associated with improvement in the arthritis but also with the development of a pleural effusion (23). The main goal of therapy should be to prevent the progressive pleural fibrosis that may necessitate a decortication in a small percentage of patients (1,4,21,24,25). There are no controlled studies evaluating the efficacy of corticosteroids or nonsteroidal anti-inflammatory drugs in the treatment of rheumatoid pleural effusion. It is recommended that patients be treated with nonsteroidal anti-inflammatory drugs such as aspirin or ibuprofen for 8 to 12 weeks initially. If the pleural effusion persists and if the joint symptoms are not well controlled, then appropriate therapy should be directed toward the rheumatologic problem. If the only symptomatic problem is the pleural disease, then the patient should have a therapeutic thoracentesis and possibly an intrapleural injection of corticosteroids. There have been two reports concerning the intrapleural injection of corticosteroids; the first (22) had two patients, and the intrapleural corticosteroids were ineffective; the second (26) had one patient who seemed to respond to one injection of 120 mg of depomethylprednisolone.

Decortication should be considered in patients with thickened pleura who are symptomatic with dyspnea. Computed tomographic examination is useful in delineating the extent of the pleural thickening. In patients with pleural effusions, the significance of the pleural thickening can be gauged by measuring the pleural pressure serially during a therapeutic thoracentesis (see Chapter 28). If the pleural pressure drops rapidly as pleural fluid is removed, the lung is trapped by the pleural disease (27), and decortication should be considered. The decortication procedure is difficult to perform in patients with rheumatoid pleuritis because it is not easy to develop a plane between the lung and the fibrous peel. Therefore, air leaks persist longer than usual after decortication (25). Nevertheless, decortication can substantially improve the quality of life of some patients with dense pleural fibrosis secondary to rheumatoid disease.