Pleurisy: Infection in the Pleura – Causes and Treatment

It is the inflammation of the laminar layers that cover the lungs (the pleura).

The most common symptom of pleurisy is an acute pain in the chest when breathing deeply. Sometimes the pain is also felt in the shoulders.

The pain can be worse when coughing, sneezing and moving, and it can be relieved by taking deep, gentle breaths. Other symptoms may include shortness of breath and a dry cough.

Visit your GP if you experience the above symptoms. Seek immediate medical help if your chest pain is severe, particularly if you also have other symptoms, such as coughing up blood, nausea, or sweating.

When to see your GP

Usually, pleurisy can be diagnosed by studying its symptoms. Your GP can listen to your chest to check for the distinctive dry sound, or a crunch that suggests that you may have pleurisy.

More tests may be needed to identify the underlying cause of your pleurisy and to assess its severity. These may include:

  • Blood tests to determine if you have an infection or an autoimmune condition.
  • Chest radiographs.
  • An ultrasound.
  • A computed tomography (CT).
  • A biopsy – a small sample of pleural or lung tissue is removed for further testing.

What causes pleurisy?

Most cases are the result of a viral infection (such as the flu) or a bacterial infection (such as pneumonia).

In more rare cases, pleurisy may be caused by conditions such as a blood clot that blocks blood flow to the lungs (pulmonary embolism) or lung cancer.

Pleurisy can affect people of all ages, but people 65 and older are at greater risk because they are more likely to develop a chest infection.

Treatment

The treatment for pleurisy depends on the underlying cause.

For example, pleurisy caused by a viral infection often resolves without treatment.

However, pleurisy caused by a bacterial infection is usually treated with antibiotics, and people who are frail or already in poor health can be admitted to the hospital.

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, are often used to relieve chest pain associated with pleurisy.

If excess fluid accumulates between the pleural layers, it may be necessary to drain the fluid to avoid breathing difficulties.

Causes

Pleuritis is the inflammation of the pleura. It is usually caused by another condition, such as an infection, but sometimes no cause can be identified.

The pleura are two thin sheets of tissue that separate the lungs and the rib cage. One joins the rib cage and the other joins the lungs.

Between the pleural laminae is a thin layer of fluid that lubricates the pleura, helping to reduce friction when inhaling and exhaling.

When there is inflammation, the surfaces of the two layers can become rough and the liquid can become sticky. This can cause the layers to touch, resulting in pain and discomfort.

Infection

An infection is the most common cause of pleurisy. Any type of infection has the potential to spread to the pleura, but viral infections are generally responsible. Viruses known to cause pleurisy include:

  • The influenza virus (flu).
  • The Epstein-Barr virus – which causes glandular fever.
  • Cytomegalovirus (CMV) – a common virus that is found in most people, which usually does not cause noticeable symptoms.
  • Parainfluenza.

In some cases, pleurisy is caused by bacteria, such as:

Streptococcal bacteria – often associated with pneumonia, throat infections and some types of skin infections, such as impetigo and cellulitis.

Staphylococcal bacteria – often associated with skin infections, food poisoning and, more seriously, blood poisoning (sepsis).

Methicillin-resistant Staphylococcus aureus can cause pleurisy, especially in hospitalized patients. It is a type of bacteria with a resistance to a series of commonly used antibiotics.

Other causes

Other possible causes of pleurisy are:

  • Injury – if the ribs are bruised or fractured, the pleura may swell
  • Pulmonary embolism – a blood clot that develops inside the lungs.
  • Sickle cell anemia: a blood disorder that usually affects people of African or Caribbean descent.
  • Chemotherapy and radiotherapy.
  • VIH about SIDA.
  • Lung cancer.
  • Mesothelioma – a type of cancer caused by the inhalation of asbestos.

Autoimmune diseases, such as rheumatoid arthritis and lupus, are other possible causes of pleurisy.

Under these conditions, something goes wrong with the immune system (the body’s natural defense against infection and disease) and begins to attack healthy tissue.

Treatment

The treatment of pleurisy usually involves relieving pain and treating the underlying cause of the disease.

If treated promptly, pleurisy often resolves without any permanent damage to the lungs.

Pain treatment

Chest pain associated with pleurisy can be treated with a type of analgesic known as nonsteroidal anti-inflammatory drugs (NSAIDs). The most common is ibuprofen.

If NSAIDs are ineffective or inadequate, you may be prescribed another analgesic, such as paracetamol or codeine.

It may seem strange, but lying on the side of the chest that hurts can also help reduce the pain.

Treat the underlying cause

It may also be necessary to treat the underlying cause of your pleurisy.

If you have pleurisy caused by a bacterial infection, you will need antibiotic treatment.

Depending on the severity of your symptoms, this may be tablets or injections. Sometimes combinations of different antibiotics are used.

However, if your pleurisy is caused by a viral infection, additional treatment may not be necessary, since the infection usually resolves after a few days.

In cases where your symptoms are particularly severe or you are already in poor health, you may need to be admitted to the hospital so they can stabilize your basic life functions.