Pleurisy

Causes

Pleurisy occurs when the pleural membranes become inflamed, usually due to an infection of the airways with viruses or bacteria. During inflammation, the surfaces become rough and the fluid can get sticky. This causes the two membranes to rub together, causing pain in the chest.

Pleurisy causes inflammation and swelling of the pleural membranes that surround the lungs. 

Infection

Any type of infection can lead to pleurisy, but the most common cause is a virus that spreads from the airway to the lining of the lungs. Viruses known to cause pleurisy include cytomegalovirus, Epstein-Barr virus and those that also cause influenza and parainfluenza. Less commonly, pleurisy may be caused by a bacterial infection, such as the type that causes pneumonia or tuberculosis.

Viruses and bacteria irritate the pleural membranes in the same way they irritate the lining of the nose and airways during a common cold.

Other causes

Any other factor that results in damage and inflammation to the lung surface or pleural membranes can cause pleurisy. Some examples include a chest injury, blood clot in a lung (pulmonary embolism), collapsed lung (pneumothorax) or lung cancer.

Certain conditions that cause inflammation may also affect the linings of the lungs. For example rheumatoid arthritis, inflammatory bowel disease or lupus can lead to pleurisy.

In most cases, pleurisy related to an underlying lung problem or medical condition will have an additional set of symptoms related to the cause.

Types

Pleurisy can be described as 'wet' or 'dry', depending on whether a build-up of fluid occurs in the pleural space between the two pleural membranes.

Wet pleurisy

In wet pleurisy, an abnormal volume of fluid collects in the pleural space. Sometimes the fluid is produced as part of the body's natural immune response to infection, or it may be due to poor drainage. The medical term for this build-up of fluid is pleural effusion.

Although a large amount of fluid can reduce pain by preventing the pleural membrane from rubbing together, the related increase in pressure can lead to complications, such as a collapsed lung or infection.

Pleural effusion is the build-up of fluid that occurs in 'wet' pleurisy. 

Dry pleurisy

As the name suggests, dry pleurisy describes inflammation of the lung lining without abnormal fluid production. Sometimes, dry pleurisy can develop into wet pleurisy over time.

Signs and symptoms

The most common symptom of pleurisy is a moderate to severe stabbing pain in the chest that feels worse during breathing, coughing or sneezing. Sometimes, the pain may also be felt in the neck, back or shoulder. It may be continuous, or it may come and go.

Other symptoms of pleurisy include:

• Fever and chills;
• An ongoing dry cough;
• Fast, shallow breathing, and;
• Shortness of breath.

Symptoms of pleurisy usually last between a few days to about two weeks.

Methods for diagnosis

A diagnosis of pleurisy is usually based upon symptoms and characteristic findings from listening to the chest with a stethoscope. Your doctor may also collect a blood sample or look more closely at your chest and lungs using an X-ray, ultrasound or computerized tomography (CT) scan.

Types of treatment

Treatments for pleurisy will depend on the underlying cause.

For example, pleurisy caused by a viral infection usually clears up after a few days without the need for prescription medication. However, your doctor may recommend rest and an over-the-counter medication, such as acetaminophen or ibuprofen, to help control the pain.

In contrast, you may be prescribed an antibiotic medication if your pleurisy is caused by a bacterial infection.

Potential complications

Potential complications of pleurisy include:

• Breathing difficulties;
• Build-up of fluid around the lungs (pleural effusion);
• A collapsed lung (pneumothorax), and;
• Infection of fluid in the pleural space.

Prognosis

The outlook for pleurisy differs from person to person, depending on the cause. Pleurisy caused by a viral infection usually clears on its own in a few days without any particular treatment, while pleurisy caused by a bacterial infection can also be successfully treated in most cases, but complications and lasting lung damage are more likely.

Prevention

Although pleurisy is not technically contagious, the viruses and bacteria that cause it may be spread by coughing, sneezing and having close contact with infected people. For this reason, it may be possible in some cases to prevent pleurisy by avoiding people who are unwell and staying away from organized activities if you have an infection. Similarly, practicing good hygiene habits may help to prevent the spread of viruses and bacteria.

Vaccinations against Streptococcus pneumonia (pneumococcal bacteria), Haemophilus influenzae type B (Hib) and the seasonal flu virus may also help to prevent the infections that could lead to pleurisy.