Pleuritis and pleurisy are two terms that are often used synonymously, although pleuritis is the inflammation of the pleura while pleurisy refers to any irritation of the pleura that leads to pain (pleuritic pain). the signs, symptoms and causes of both conditions often overlap.

Pleurisy is more often associated with chest pain that is described as a sharp stabbing pain. it may exacerbate during breathing and coughing. the nature of pain in pleurisy is described further under pleuritic pain. Depending on the part of the pleura that is irritated, the pain may refer to the neck, shoulder or upper abdomen.

Other signs and symptoms that may be seen with pleurisy includes :

• Pleural effusion which is the fluid around the lungs.
• Shortness of breath as a result of shallow inhalation due to pain, restricted expansion of the lung due to a pleural effusion, or pathology of the air sacs in the lung which is associated with pleural involvement.
• Dry cough although a productive cough may be seen with bronchitis and pneumonia.
• Fever with infectious causes, certain autoimmune diseases and sometimes with malignancies.
• Pleural frictional rub is the sound similar to stiff leather creaking which is seen with pleuritis and is most prominent in fibrinous pleuritis. it is known as a pleuro-pericardial rub if it is only audible near the pericardium during deep inspiration. Read more on pericardial frictional rub under pericarditis symptoms.

Infections

The most common cause of pleuritis is a viral infection.while it may arise with viral infections of surrounding areas or even systemic infections, viral pleuritis is often seen in outbreaks caused by the coxsackie B virus. it tends to affect adolescents and young adults and is a self limiting infection that resolves with just supportive treatment.

Other common causes of pleuritis is often related to infection of the lungs as is seen with pneumonia and tuberculosis. Spread to the pleura may not always occur but is usually seen as the disease progresses. A lung abscess or empyema (pus within the pleural cavity) may also involve the pleura. Infection may also spread from the pericardium in infectious pericarditis.

Non-infectious

Trauma to the chest, exposure to radiation in the treatment of pulmonary and mediastinal cancers and hypersensitivity to certain drugs may cause pleuritis. This is similar to the causes of pericarditis and it is not uncommon for both the pleura and pericardium to be affected simultaneously.

Other non-infectious conditions that may affect the lung and also involve the pleura includes bronchiectasis (non-infectious causes), lung infarcts and pulmonary embolism. Pleuritis may also be seen with a spontaneous pneumothorax.

Non-infectious causes may also include systemic conditions and connective tissue diseases like rheumatoid arthritis, systemic lupus erythematosus (SLE) and uremia.

Tumors

Primary malignant tumor of the pleura is known as a mesothelioma and is often associated with asbestos exposure. Tumors of the lung or bronchi, mediastinum and secondary spread from distant site (matastases) may involve the pleura.

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