What is pleurisy

Pleurisy is an inflammation of the pleura, a large, thin sheet of tissue that wraps around the outside of your lungs and lines the inside of your chest cavity (Figures 1 and 2). These two large, thin layers of tissue called the pleura separate your lungs from your chest wall. One layer wraps around the outside of the lungs (visceral pleura). The other layer lines the inner chest wall (parietal pleura). Between these two layers is a very thin space called the pleural space, that’s usually filled with a very small amount of fluid that helps the two layers of the pleura glide smoothly past each other as your lungs breathe air in and out. The layers act like two pieces of smooth satin gliding past each other, allowing your lungs to expand and contract when you breathe without any resistance from the lining of the chest wall. Pleurisy occurs when the two layers of the pleura become irritated and inflamed, rubbing against each other like two pieces of sandpaper, producing pain when you inhale and exhale. The pleuritic pain lessens or stops when you hold your breath. Pleurisy is usually caused by a chest infection – either a viral infection (such as influenza) or a bacterial infection (such as pneumonia).

The main symptom of pleurisy is a sharp or stabbing pain in your chest that gets worse when you breathe in deeply or cough or sneeze. The pain may stay in one place or it may spread to your shoulder or back. Sometimes it becomes a fairly constant dull ache. Depending on what’s causing the pleurisy, you may have other symptoms, such as:

• Shortness of breath
• A cough
• Fever and chills
• Rapid, shallow breathing
• Unexplained weight loss
• A sore throat followed by pain and swelling in your joints

Some people also get a pleural effusion, which is when the inflammation causes a large build-up of fluid between the linings of the lung and chest wall.

This can help relieve the symptoms of pleurisy because the linings no longer rub against each other. However, it can also cause compression of the lungs, leading to breathing problems.

Is pleurisy contagious?

Depends on the cause of the pleurisy. Pleurisy caused by the flu or bacterial infection is contagious.

How long does pleurisy last?

Recovery and how long does pleurisy last depends on the cause of the pleurisy.

Health problems that may develop from pleurisy include:

• Breathing difficulty
• Fluid buildup between chest wall and lung (pleural effusion)
• Complications from the original illness

Human lungs

The lungs are soft, spongy, cone-shaped organs in the thoracic (chest) cavity. The lungs consist largely of air tubes and spaces. The balance of the lung tissue, its stroma, is a framework of connective tissue containing many elastic fibers. As a result, the lungs are light, soft, spongy, elastic organs that each weigh only about 0.6 kg (1.25 pounds). The elasticity of healthy lungs helps to reduce the effort of breathing.

The left and right lungs are situated in the left and right pleural cavities inside the thoracic cavity. They are separated from each other by the heart and other structures of the mediastinum, which divides the thoracic cavity into two anatomically distinct chambers. As a result, if trauma causes one lung to collapse, the other may remain expanded. Below the lungs, a thin, dome-shaped muscle called the diaphragm separates the chest from the abdomen. When you breathe, the diaphragm moves up and down, forcing air in and out of the lungs. The thoracic cage encloses the rest of the lungs.

Each lung occupies most of the space on its side of the thoracic cavity. A bronchus and some large blood vessels suspend each lung in the cavity. These tubular structures enter the lung on its medial surface.

Parietal refers to a membrane attached to the wall of a cavity; visceral refers to a membrane that is deeper—toward the interior—and covers an internal organ, such as a lung. Within the thoracic (chest) cavity, the compartments that contain the lungs, on either side of the mediastinum, are lined with a membrane called the parietal pleura. A similar membrane, called the visceral pleura, covers each lung.

The parietal and visceral pleural membranes are separated only by a thin film of watery fluid (serous fluid), which they secrete. Although no actual space normally exists between these membranes, the potential space between them is called the pleural cavity.

A thin lining layer called the pleura surrounds the lungs. The pleura protects your lungs and helps them slide back and forth against the chest wall as they expand and contract during breathing. A layer of serous membrane, the visceral pleura, firmly attaches to each lung surface and folds back to become the
parietal pleura. The parietal pleura, in turn, borders part of the mediastinum and lines the inner wall of the thoracic cavity and the superior surface of the diaphragm.

Figure 1. Lungs anatomy and pleural space

Figure 2. Lungs pleura and pleural cavity

Pleurisy causes

What causes pleurisy

Most cases of pleurisy are caused by a virus, such as the flu (influenza) virus.

Less common causes of pleurisy include:

• Bacterial infections, such as pneumonia and tuberculosis, and infections from parasites
• Fungal infection
• A blood clot that travels through the blood vessels to the lungs (pulmonary embolism)
• injury – if the ribs are bruised or fractured, the pleura can become inflamed
• Cancer, such as lung cancer, lymphoma, and mesothelioma
• Autoimmune conditions, such as rheumatoid arthritis and lupus
• Chest and heart surgery, especially coronary artery bypass grafting
• Certain medications
• Rib fracture
• Lung diseases, such as lymphangioleiomyomatosis or asbestosis
• Inflammatory bowel disease
• Certain inherited diseases, such as sickle cell disease or Familial Mediterranean fever, an inherited condition that often causes fever and swelling in the abdomen or lungs

Other causes of pleurisy include chest injuries, pancreatitis (an inflamed pancreas), and reactions to certain medicines. Reactions to certain medicines can cause a condition similar to lupus. These medicines include procainamide, hydralazine, and isoniazid.

Sometimes doctors can’t find the cause of pleurisy.

Pleurisy symptoms

The signs and symptoms of pleurisy might include:

• Sharp or stabbing pain chest pain that worsens when you breathe, cough or sneeze
• Shortness of breath — because you are trying to minimize breathing in and out
• A cough — only in some cases
• A fever — only in some cases

Pain caused by pleurisy also might affect your shoulders or back.

In some cases of pleurisy, fluid builds up in the small space between the two layers of tissue (pleural space). This is called pleural effusion. When there is a fair amount of fluid, pleuritic pain lessens or disappears because the two layers of pleura are no longer in contact. A large amount of fluid in the pleural space can create pressure, compressing your lung to the point that it partially or completely collapses. This makes breathing difficult and might cause you to cough. The extra fluid can also become infected. This is called an empyema. An empyema is often accompanied by fever.

Pleurisy diagnosis

Your doctor will find out if you have pleurisy or another pleural disorder by taking a detailed medical history and doing a physical exam with a stethoscope and several diagnostic tests, including:

• Blood tests. A blood test might tell your doctor if you have an infection. Other blood tests also might detect an autoimmune disorder, such as rheumatoid arthritis or lupus, in which the initial sign is pleurisy.
• Arterial blood gas tests, which show how well your lungs are taking in oxygen. For this test, a blood sample is taken from an artery, usually in your wrist. The blood’s oxygen and carbon dioxide levels are checked. This test shows how well your lungs are taking in oxygen.
• Chest X-ray. A chest X-ray can show if your lungs are fully inflating or if there is air or fluid between the lungs and ribs. Your doctor might recommend a special type of chest X-ray in which you lie on your side (decubitus chest X-ray).
• Computerized tomography (CT) scan. In a CT scan, a computer translates information from X-rays into images of thin sections (slices) of your chest, producing more-detailed images. A chest CT scan can show if there is a blood clot in the lung or find other causes of pleuritic pain.
• Ultrasound. This imaging method uses high-frequency sound waves to produce precise images of structures within your body. Your doctor might use ultrasound to determine whether you have a pleural effusion.
• Electrocardiogram (ECG or EKG). Your doctor might recommend this heart-monitoring test to rule out certain heart problems as a cause for your chest pain.

Diagnostic procedures

In some cases, your doctor might remove fluid and tissue from the pleural space for testing. Procedures might include:

• Thoracentesis. To remove fluid for laboratory analysis, your doctor might suggest thoracentesis. In this procedure, your doctor injects a local anesthetic between your ribs to the area where fluid was seen on your imaging studies. Next your doctor inserts a needle through your chest wall between your ribs to remove fluid for laboratory analysis. Your doctor might insert the needle with the help of ultrasound guidance.
• Thoracoscopy or pleuroscopy. If tuberculosis or cancer is a suspected cause of your condition, your doctor might perform a procedure that allows for direct visualization inside your chest to look for any abnormalities or to obtain a tissue sample (biopsy) if needed.
• Biopsy. Your doctor may suspect that tuberculosis or cancer has caused fluid to build up in your pleural space. If so, he or she may want to look at a small piece of the pleura under a microscope. To take a tissue sample, your doctor may do one of the following procedures:
  • Insert a needle into your chest to remove a small sample of the pleura’s outer layer.
  • Insert a tube with a light on the end (endoscope) into tiny cuts in your chest wall so that he or she can see the pleura. Your doctor can then snip out small pieces of tissue. This procedure must be done in a hospital. You’ll be given medicine to make you sleep during the procedure.
  • Snip out a sample of the pleura through a small cut in your chest wall. This is called an open pleural biopsy. It’s usually done if the sample from the needle biopsy is too small for an accurate diagnosis. This procedure must be done in a hospital. You’ll be given medicine to make you sleep during the procedure.

Your doctor will look at the fluid under a microscope to determine what’s causing the fluid buildup. If the fluid is infected, treatment involves antibiotics and draining the fluid. If the infection is tuberculosis or from a fungus, treatment involves long-term use of antibiotics or antifungal medicines. If the fluid is caused by tumors of the pleura, it may build up again quickly after it’s drained. Sometimes antitumor medicines will prevent further fluid buildup. If they don’t, the doctor may seal the pleural space.

Pleurisy treatment

Treatments used in pleurisy and pleural effusion focus primarily on the underlying cause.

How to treat pleurisy

To relieve symptoms, your doctor may recommend:

• Acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, to control pain
• Codeine-based cough syrups to control a cough
• Lying on the painful side to make you more comfortable. It seems strange, but lying on the side of your chest that hurts may also help reduce the pain.
• Breathing deeply and coughing to clear mucus as the pain eases
• Getting plenty of rest.

The outcome of pleurisy treatment depends on the seriousness of the underlying disease. If the condition that caused pleurisy is diagnosed and treated early, a full recovery is typical.

Treating the underlying cause of pleurisy

If your pleurisy is caused by a viral infection, it’ll usually get better on its own after a few days.

If it’s caused by a bacterial infection, you’ll need antibiotics. Depending on the severity of your symptoms, this may be either tablets or injections.

If your symptoms are particularly severe or you’re already in poor health, you may need to be admitted to hospital.

Treating pleural effusion

In some cases, pleurisy causes a build-up of excess fluid around the lungs called pleural effusion.

Pleural effusion can lead to shortness of breath that gets progressively worse. This is more likely if pleurisy is caused by pulmonary embolism or a bacterial infection.

If pleural effusion doesn’t clear up as your pleurisy is treated or you’re very short of breath, the fluid may need to be drained by inserting a needle or tube through the chest wall.

A procedure called thoracentesis is used to remove fluid from the pleural space. The doctor inserts a needle or a thin, hollow, plastic tube through the ribs in the back of your chest into your chest wall. A syringe is attached to draw fluid out of your chest.

• If your doctor needs to remove a lot of fluid, he or she may use a chest tube. Your doctor will inject a painkiller into the area of your chest wall where the fluid is. He or she will then insert a plastic tube into your chest between two ribs. The tube will be connected to a box that suctions out the fluid. Your doctor will use a chest x ray to check the tube’s position.
• Your doctor also can use a chest tube to drain blood and air from the pleural space. This process can take several days. The tube will be left in place, and you’ll likely stay in the hospital during this time.

This can be done under general anesthetic or local anesthetic. You may need to stay in hospital for a few days if a lot of fluid has to be drained away.

The fluid sample that was removed during thoracentesis will be checked under a microscope. This can tell your doctor what’s causing the fluid buildup, and he or she can decide the best way to treat it.

If the fluid is infected, treatment will involve antibiotics and drainage. If you have tuberculosis or a fungal infection, treatment will involve long-term use of antibiotics or antifungal medicines.

If tumors in the pleura are causing fluid buildup, the fluid may quickly build up again after it’s drained. Sometimes antitumor medicines will prevent further fluid buildup. If they don’t, your doctor may seal the pleural space. Sealing the pleural space is called pleurodesis.

For this procedure, your doctor will drain all of the fluid out of your chest through a chest tube. Then he or she will push a substance through the chest tube into the pleural space. The substance will irritate the surface of the pleura. This will cause the two layers of the pleura to stick together, preventing more fluid from building up.

Chemotherapy or radiation treatment also may be used to reduce the size of the tumors.

If heart failure is causing fluid buildup, treatment usually includes diuretics (medicines that help reduce fluid buildup) and other medicines.

Pleurisy treatment at home

The following steps might help relieve symptoms related to pleurisy:

• Take medication. Take medication such as ibuprofen (Advil, Motrin IB, others) as needed to relieve pain and inflammation.
• Get plenty of rest. Find the position that causes you the least discomfort and try to stay in it. Even when you start to feel better, be careful not to overdo it.