Review of pulmonary manifestations of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic autoinflammatory disorder that primarily affects joints. However, RA can involve extra-articular structures as well, including the lungs, affecting significant morbidity and mortality, though the precise mechanisms of extra-articular RA are still under investigation. Accurate diagnosis of these conditions can be challenging and requires a multidisciplinary approach. This review aims to describe proposed mechanisms of pulmonary RA and characterize common, clinically relevant pulmonary manifestations of RA, including parenchymal disease (interstitial lung disease and multiple pulmonary nodules), small and large airway involvement, and pleural effusions. In particular, CT imaging may reveal developing pulmonary disease before clinical symptoms present, revealing the importance of maintaining a high degree of suspicion for RA-related pulmonary disease.