Pleurisy

Did You Know?

• Pleurisy can lead to cor pulmonale, a form of pulmonary heart disease that may cause heart failure if untreated.
• A pleural effusion can occur without pleurisy, for example due to pneumonia, heart failure, cancer, or pulmonary embolism.

Signs and symptoms

The defining symptom is a sudden sharp, stabbing, burning, or dull pain in the right or left side of the chest during breathing, especially on inhalation and exhalation. The pain worsens with deep breathing, coughing, sneezing, or laughing, and may remain localized or spread to the shoulder or back. Sometimes it becomes a constant, dull ache. Depending on the underlying cause, pleuritic chest pain may be accompanied by a dry cough, fever and chills, rapid shallow breathing, shortness of breath, fast heart rate, or sore throat followed by joint pain and swelling. Pleurisy often involves complications affecting the pleural space. In some cases, excess fluid accumulates in the pleural space, a condition called pleural effusion. This fluid can separate the pleural layers, relieving the rubbing pain, but a large effusion may collapse the lung and cause breathing difficulty. If the fluid becomes infected, it forms an abscess known as an empyema. Fibrinous exudates in the fluid may indicate fibrinous pleurisy, sometimes a later stage. Air or gas in the pleural space, termed pneumothorax, can result from acute lung injury, lung disease such as emphysema, or lung procedures; its most common symptom is sudden one-sided lung pain and shortness of breath, and it may collapse the lung. Blood in the pleural space, called hemothorax, typically follows chest injury or heart or chest surgery, and can also collapse the lung or cause shock from insufficient blood flow to organs.

Causes

Viral infection is the most common cause of pleurisy, with implicated viruses including coxsackie B virus, HRSV, CMV, adenovirus, EBV, parainfluenza, influenza, and COVID-19. Many other conditions can produce pleuritic chest pain: aortic dissections; autoimmune disorders such as systemic lupus erythematosus, autoimmune hepatitis, rheumatoid arthritis, and Behçet's disease; bacterial infections associated with pneumonia and tuberculosis; chest injuries; familial Mediterranean fever; fungal or parasitic infections; heart surgery; cardiac problems like ischemia and pericarditis; inflammatory bowel disease; lung cancer and lymphoma; other lung diseases such as cystic fibrosis, sarcoidosis, asbestosis, lymphangioleiomyomatosis, and mesothelioma; pneumothorax; and pulmonary embolisms. When the pleural space fills with fluid (pleural effusion), chest pain may ease but shortness of breath can develop. Some cases are idiopathic, meaning no exact cause is found.

Diagnosis

Diagnosis of pleurisy or other pleural conditions relies on medical history, physical examination, and diagnostic tests, aiming to rule out other causes and identify the underlying disorder. During auscultation with a stethoscope, a pleural friction rub—a rough, scratchy sound from inflamed pleurae rubbing together—may be heard. Based on exam findings, further tests may be performed. A chest X-ray can reveal air or fluid in the pleural space, as well as potential causes such as pneumonia, a fractured rib, or a lung tumor. An X-ray taken while lying on the painful side may show fluid or changes in fluid position not seen on a vertical X-ray. Blood tests can detect bacterial or viral infections, pneumonia, rheumatic fever, pulmonary embolism, or lupus. Electrocardiography helps determine if a heart condition contributes to symptoms. Ultrasonography can locate fluid in the chest and show some tumors, but sound waves are scattered by air, so lung imaging is not possible. CT scanning provides computer-generated lung images that can show fluid pockets, pneumonia, lung abscess, or tumors. MRI uses powerful magnets to display pleural effusions and tumors. Arterial blood-gas sampling, usually from the wrist, checks oxygen and carbon dioxide levels to assess lung function. If pleural effusion is suspected and located, diagnostic thoracentesis—inserting a needle or thin plastic tube through the chest wall—removes fluid for testing.

Treatment

Treatment goals include relieving symptoms, removing fluid, air, or blood from the pleural space, and addressing the underlying condition. Large accumulations of fluid, air, or blood may collapse the lung if not drained. Thoracentesis uses a needle or thin tube inserted through the ribs to draw out fluid. For larger amounts, a chest tube is inserted between two ribs after local anesthesia, connected to suction, and its position is checked by X-ray; it may remain for several days, often requiring hospital stay. If fluid contains thick pus or blood clots, fibrinolytics may be instilled through the tube; if drainage fails, surgery may be needed. Medications for symptom relief include paracetamol (acetaminophen) or anti-inflammatory agents such as indomethacin (brand name Indocin), the only one studied for pleurisy, and codeine-based cough syrups to control cough. Corticosteroids (for tuberculous pleurisy), tacrolimus (Prograf), and methotrexate (Trexall, Rheumatrex) may have a role, but further studies are needed. Management may involve lying on the painful side, breathing deeply and coughing to clear mucus as pain eases to prevent pneumonia, and resting. Ideally, treatment targets the underlying cause. Infected pleural fluid requires antibiotics and drainage; tuberculosis or fungal infections need long-term antibiotics or antifungals.