The pleura is a thin membrane that surrounds the lungs and lines the chest cavity. It allows the lungs to move smoothly within the chest during breathing. Any condition that causes inflammation or injury to the pleura is known as a pleural disease. Pleural diseases can range from mild to severe and sometimes require medical intervention. This article aims to provide an overview of some common pleural diseases, their causes, symptoms, and treatments.
Pleural Effusion
One of the most common pleural diseases is pleural effusion, which occurs when excess fluid collects in the pleural space between the lungs and chest wall. This fluid hampers the full expansion of the lungs during breathing. Some potential causes of a pleural effusion include:
- Heart failure: When the heart is not pumping efficiently, fluid builds up in the lungs and flows back into the pleural space.
- Infection: Bacterial pneumonia or tuberculosis are infectious causes. Viruses like hepatitis can also cause a transudative effusion.
- Cancer: Lung cancer, breast cancer, or lymphoma that has spread to the lungs or pleura often leads to a malignant pleural effusion.
- Kidney or liver failure: In end-stage kidney or liver disease, proteins leak into the blood vessels and result in fluid accumulation in the pleural space.
The excess fluid is usually diagnosed with a chest X-ray or ultrasound. Treatment focuses on draining the fluid with a thoracentesis procedure and addressing the underlying cause. In cancer cases, a pleurodesis may be done to prevent re-accumulation.
Pneumothorax
A pneumothorax occurs when air leaks into the pleural space, causing the lung to collapse. This may happen due to an injury that causes a tear in the lung or, in some cases, for no apparent reason. Symptoms include sharp chest pain, shortness of breath, and a cough. A spontaneous pneumothorax is often seen in tall, thin young men who smoke.
Treatment depends on the severity and cause. A small, asymptomatic pneumothorax may only require rest and follow-up X-rays. Larger cases may need a chest tube inserted to drain air and re-expand the lung. Surgery (pleurodesis or pleurectomy) is sometimes needed for recurring pneumothoraces.
Pleurisy
Also known as pleuritis, pleurisy occurs due to inflammation of the pleura, usually due to a viral or bacterial infection. It causes sharp, localized chest pain that worsens on breathing deeply or coughing. The trigger is often a respiratory infection, but other potential causes include pulmonary embolism, rheumatoid arthritis, lupus, or an appendicitis rupture into the chest.
Treatment focuses on relieving pain and treating the underlying condition. Over-the-counter pain relievers and applying a heated pad can help. Antibiotics may be prescribed if an infection is causing the inflammation. The condition is usually self-limiting and resolves within a few weeks.
Mesothelioma
This rare type of cancer arises from the pleura or peritoneum. Its development is strongly associated with asbestos exposure, either through occupation or environmental exposure. Symptoms include chest wall pain, breathlessness, and a cough.
Diagnosis involves imaging tests and biopsy of pleural tissue or fluid. Staging helps determine the extent of disease spread. Treatment options may include surgery, chemotherapy, and radiation therapy. However, mesothelioma has a poor prognosis with average survival of 12-21 months. Preventive measures include strict control of asbestos at workplaces and public buildings.
Other Pleural Disease
Some less common pleural diseases include:
- Pleural plaque: Benign patches formed in the pleura due to asbestos exposure visible on CT scan.
- Fibrothorax: Pleural fibrosis and thickening due to tuberculosis or prior pleurodesis/effusion. Causes restrictive lung defects.
- Hemothorax: Collection of blood in the pleural space, usually due to trauma or a spontaneous bleeding diathesis.
- Empyema: Pus collection in the pleural space due to a pyogenic bacterial infection of the pleura. Empyema is a medical emergency requiring drainage and antibiotics.
In summary, the pleura can be involved in many lung and systemic diseases. Diagnosis often includes imaging and thoracentesis for effusions or bleeding. Treatment focuses on the underlying trigger while managing pleural abnormalities. With advances in management of infections and cancers, outcomes for many pleural diseases have significantly improved in recent years.
