The pleura is a thin, two-layered membrane surrounding the lungs and lining the chest cavity. The inner visceral pleura covers the lung, while the outer parietal pleura adheres to the chest wall. These layers normally glide smoothly, allowing unrestricted lung movement. Pleural fibrosis occurs when this membrane scars and thickens, restricting normal lung expansion.
Causes and Risk Factors
Exposure to asbestos is a recognized cause of pleural fibrosis. Inhaling these fibers can trigger chronic inflammation in the pleura, leading to scar tissue formation. This scarring, which may appear as focal plaques or diffuse thickening, can develop over 20 years after initial exposure.
Infections of the pleural space can also result in fibrosis. Severe inflammation from infections like bacterial pneumonia, tuberculosis, and empyema (a collection of pus in the pleural cavity) can lead to fibrous tissue development.
Inflammatory and autoimmune diseases can cause pleural fibrosis. Conditions like rheumatoid arthritis and systemic lupus erythematosus can lead to pleurisy, or pleural inflammation. This inflammation may eventually cause fibrous thickening. Uremic pleurisy, linked to kidney failure, also contributes to pleural scarring.
Medical procedures can also lead to pleural fibrosis. Coronary artery bypass graft surgery, radiation therapy to the chest, and hemothorax (blood in the pleural space) are potential causes. Additionally, drug-induced pleuritis, where certain medications trigger pleural inflammation, can contribute to the condition.
Recognizing the Symptoms
Individuals experiencing pleural fibrosis often report progressive shortness of breath, particularly with physical exertion. This symptom arises because the thickened pleura restricts the lung’s ability to fully expand and take in air. Even mild activities, such as walking up stairs, may become challenging.
A persistent, dry cough is common with pleural fibrosis. This cough is non-productive, meaning it does not bring up mucus or phlegm. It can be a constant source of irritation and may worsen with increased activity or deep breaths.
Chest pain or discomfort is also common with pleural fibrosis. This pain can manifest as a dull ache or a sensation of tightness in the chest. It occurs because the fibrotic pleura loses its natural elasticity and can pull on surrounding structures during breathing, leading to discomfort. Symptoms tend to become more pronounced as the fibrosis progresses, impacting daily life and exercise capacity.
Diagnostic Process
The diagnostic process for pleural fibrosis typically begins with a thorough clinical evaluation. A healthcare provider will review the patient’s medical history, noting any past exposures, infections, or underlying conditions that could contribute to pleural inflammation. A physical examination may reveal decreased breath sounds or other signs of restricted lung expansion.
Imaging tests are important for diagnosing pleural fibrosis. A chest X-ray is often the initial study, revealing signs of pleural thickening or calcification. While a chest X-ray can indicate thickening, a high-resolution computed tomography (HRCT) scan provides a more detailed view of the pleural membranes, allowing for precise identification of fibrous tissue and its distribution.
Pulmonary Function Tests (PFTs) assess lung capacity and function, measuring how much air the lungs can hold and how efficiently it moves. For pleural fibrosis, PFTs typically show a restrictive ventilatory pattern, indicating the lungs cannot fully expand due to the thickened pleura.
In certain situations, a surgical biopsy may be necessary to confirm the diagnosis and rule out other lung or pleural conditions. This procedure, often performed via thoracoscopy, involves taking a small sample of pleural tissue for microscopic examination. Thoracoscopy allows direct visualization of the pleura and precise biopsy collection, providing definitive information about the fibrous tissue.
Management and Treatment Approaches
Treatment for pleural fibrosis primarily focuses on managing symptoms and addressing any underlying causes, as the scarring itself is generally considered irreversible. If an ongoing condition, such as an autoimmune disease, contributes to the fibrosis, managing that root cause can help prevent further progression. This might involve specific medications or therapies to control the inflammatory process.
Symptomatic relief is an important aspect of care. Oxygen therapy may be prescribed for significant shortness of breath, especially when lung function is severely impaired, to ensure adequate oxygen delivery. Pulmonary rehabilitation programs offer structured exercise and education to improve lung function, enhance physical endurance, and help patients cope with reduced lung capacity.
Medications like corticosteroids can reduce inflammation. While they may decrease the incidence of pleural fibrosis when administered early for conditions like rheumatoid pleurisy, their effectiveness for established fibrosis is limited. Their use is carefully considered, often for managing acute inflammation rather than reversing existing scarring.
For severe cases where the lung becomes encased by a thick, fibrous peel, a surgical procedure called decortication may be considered. This operation involves carefully removing the fibrous tissue from the lung surface, allowing it to re-expand and improve breathing. Decortication is typically reserved for symptomatic patients with documented chronicity and no significant underlying lung disease. It aims to alleviate the “trapped lung” phenomenon, where the lung cannot fully inflate due to the constricting fibrous peel.