Pleurisy (pleuritis) is an inflammation of the pleura – the lining of the chest cavity that cover the lung.
The pleura is the membrane that surrounds the lung and covers the thoracic cavity. The space between the lung and the walls of the thorax is called the pleural cavity. Normally this cavity contains a small amount of fluid (approximately 10 mL). When due to various causes the amount of the fluid increases, it is called the pleural effusion.
The most common symptom of the pleurisy is the characteristic thoracic pain.
Causes and risk factors
- The most common cause of the pleurisy is a viral infection. Coxsackie B virus, human respiratory syncytial virus, cytomegalovirus, adenovirus, Epstein-Barr virus, parainfluenza, influenza viruses are usually involved.
- The pleurisy may be the complication of the pneumonia or tuberculosis.
- Fungal infection may cause the pleurisy.
- Certain autoimmune disorders such as lupus, Still’s disease and rheumatoid arthritis may lead to the pleurisy.
- Injuries of the chest, lung cancer, mesothelioma, pulmonary embolism, pancreatitis, peritonitis are known to cause pleuritis as well.
- The congestive heart failure results in the pulmonary stasis, which causes pleural effusion due to increased pressure in the pulmonary circulation.
- Cirrhosis and renal failure (uremia) can also cause the pleural effusion due to the decreased amount of the protein in the blood (hypoproteinemia).
- Certain drugs such as methotrexate, nitrofurantoin, dantrolene, methysergide, procarbazine may cause pleurisy. Procainamide and hydralazine are known to cause so-called drug-induced lupus syndrome.
Depending on the presence of the pleural effusion in the pleural cavity two types of the pleurisy are distinguished:
- Wet pleurisy – when there is the pleural effusion in the thoracic cavity;
- Dry (fibrinous) pleurisy – the inflammation of pleura with numerous fibrinous adhesions;
The pain characteristic for the pleurisy is called a pleuritic pain and is usually sudden sharp and stabbing. This pain worsens with deep breathing, laughing or coughing. This feeling may change with the movement and in different positions, usually it is on one side of the chest. The pain may irradiate to the shoulder or the back. In some cases the pain may be dull.
A person may breath shallow to avoid the unpleasant feeling.
Other symptoms of the disease may include the dry cough, fever, shortness of breath (dyspnoe), tachypnoe (rapid breathing), tachycardia (fast heart rate). Joint pain is typical for autoimmune disorders, enlarged lymph nodes are suggestive of malignancy or viral infection.
See also: Osgood-Schlatter disease
To make the diagnosis the following examinations:
- Blood test – leucocytosis confirms the infection etiology of the disease, some tests may be performed to verify the autoimmune disorder;
- Chest X-ray is the main method to verify the presence of the pleural effusion, the dislocation of the mediastinum and athelectasis may be seen;
- Ultrasound may be helpful to estimate the pleural effusion;
- CT scan/MRI scan may help to detect the small amounts of fluid;
- ECG is required to detect possible cardiac problems;
- Diagnostic thoracentesis – a process during which a sample of fluid from the pleural cavity to perform the analysis of the fluid. This procedure is necessary to identify the nature of the pleural effusion whether it is the pus (pyothorax or pleural empyema), blood (hemothorax), lymphatic fluid (chylothorax) or the serous fluid (hydrothorax);
- Thoracoscopy, pleuroscopy with the biopsy of the pleurae is required when tuberculosis or cancer is suspected;
Treatment of the pleurisy depends on the underlying condition.
However, the pleural effusion should be drained or removed via thoracentesis, especially when the amount of the fluid is significant.. This helps to avoid the development of pleural adhesions or the lung collapse.
When the fibrous adhesions fill in the pleural cavity thoracoscopy may be required.
The procedure called pleurodesis or pleural sclerosis obliterates the possible source of the effusion usually when it is caused by cancer.
- Aspirin, ibuprofen and other NSAIDs are able to relieve the pain and cease the inflammatory reaction.
- Immunosuppressive and cytostatic therapy is required for the treatment of malignancies and autoimmune disorders.
- Antibiotics (clindamycin, ampicillin and sulbactam) are necessary when the pleuritis occurs due to bacterial infection.
- Diuretics (furosemide) are helpful to reduce the swellings and accumulation of the fluid in the thoracic cavities.
- Anticoagulants are used in the treatment of heart failure and pulmonary embolism.
- Codeine may help to relieve the coughing.