Can Rheumatoid Arthritis Cause Pleuritis?

Despite rheumatoid arthritis (RA) being primarily a disease that affects the joints, it commonly targets the lungs.

Lung diseases are caused by the immune system attacking the airways, pleura, and lung tissue. The immune attack in RA can damage the lungs in several ways. The medications used for RA treatment may also cause lung manifestations. 

• Pleural disease: The immune system attacks the pleural membrane and perturbs its structure and function. Normally, the pleura produces a small amount of lubricating fluid called pleural fluid that allows the lungs to move smoothly in the chest during breathing. RA may result in excessive secretion of the pleural fluid, a condition called pleural effusion. This fluid may also get infected. RA can cause swelling or inflammation of the pleura, a condition called pleurisy or pleuritis.
• Pulmonary fibrosis (lung scarring): Lungs are spongy organs that expand and contract during inhalation and exhalation, respectively. This movement of the lungs during breathing is ensured by its typically cellular and tissue structure. RA can attack healthy lung tissues and make them get replaced by fibrous tissue, a condition called scarring. Scarred lungs lack the flexibility of normal lungs, and thus, lung scarring compromises breathing function.
• Pulmonary nodules: Lung or pulmonary nodules are small lumps of cells within the lungs. RA can also cause nodules at other sites in the body. Lung nodules may occur due to other reasons such as infections and air pollutants. Most lung nodules do not cause any symptoms and are incidentally diagnosed on chest X-rays. They may, however, grow and cause breathing issues. Some nodules may even rupture, causing lung collapse.
• Airway obstruction: RA can cause considerable inflammation in the lungs leading to excess mucus secretion, accumulation of inflammatory cells, and swollen airways. This can particularly harm the narrow or small airways, leading to the hampered passage of air through them—a condition called airway obstruction.
• Pulmonary hypertension: A condition in which there is increased blood pressure in blood vessels leading to the lungs from the heart. RA can cause pulmonary hypertension in three main ways, which include:
  • Direct damage to the lung tissue
  • Vascular disease (blood vessel damage)
  • Thromboembolic disease (abnormal blood clotting)

Signs and symptoms of lung involvement in rheumatoid arthritis (RA) may vary depending on factors such as:

• Type of lung disease
• Its severity
• Person’s general health including the presence of any underlying health conditions

Some of the general signs and symptoms of lung disease due to RA include:

• Difficulty breathing
• Wheezing
• Cough 
• Chest pain
• Fever
• Weight loss
• Appetite loss
• Weakness 

These symptoms may be associated with other RA symptoms such as:

• Pain and swelling in one or more joints
• Symmetric arthritis (joints on both sides of the body, such as both right and left-hand joints, get affected)
• Joint stiffness particularly in the morning or after periods of rest or inactivity

Your doctor may order blood tests and imaging studies such as X-rays and CT scans to reach a definitive diagnosis.

The treatment of lung manifestations of rheumatoid arthritis (RA) involves controlling the disease process through medications to treat RA, such as disease-modifying antirheumatic drugs, corticosteroids, biological response modifiers or biologicals, and Janus kinase inhibitors.

Depending on the type of lung disease and its severity, your doctor may suggest:

• Lifestyle modifications that include avoiding smoking, including secondhand smoke, exercising, and maintaining a healthy weight. Moreover, they may suggest a healthy and balanced diet and avoiding exposure to air pollutants and allergens such as pollen and animal dander.
• Physical therapy and breathing exercises may help improve lung function and minimize the symptoms.
• Medications to treat conditions such as infections, scarring, and pulmonary hypertension.
• Regular vaccinations such as flu and pneumonia vaccines to avoid infections.
• Surgery in serious cases such as large lung nodules or cases that do not respond to conservative treatment. A lung transplant may be rarely needed.